diff --git a/PKHeX.WinForms/MainWindow/Main.cs b/PKHeX.WinForms/MainWindow/Main.cs
index b42b6f4fd..8fec9becc 100644
--- a/PKHeX.WinForms/MainWindow/Main.cs
+++ b/PKHeX.WinForms/MainWindow/Main.cs
@@ -977,9 +977,17 @@ namespace PKHeX.WinForms
                 if (drVC == DialogResult.Cancel)
                     return;
                 Legal.AllowGBCartEra = drVC == DialogResult.No; // physical cart selected
+                if (Legal.AllowGBCartEra && sav.Generation == 1)
+                {
+                    var drTradeback = WinFormsUtil.Prompt(MessageBoxButtons.YesNoCancel, "Generation 1 Save File detected. Allow tradeback from generation 2 for legallity purpose?",
+                        "Yes: Generation 2 tradeback allow" + Environment.NewLine + "No: Only consider legal pokemon possible without generation 2 games");
+                    Legal.AllowGen1Tradeback = drTradeback == DialogResult.Yes;
+                }
+                else
+                    Legal.AllowGen1Tradeback = false;
             }
             else
-                Legal.AllowGBCartEra = sav.Generation == 2;
+                Legal.AllowGBCartEra = Legal.AllowGen1Tradeback  = sav.Generation == 2;
 
             if (sav.Generation == 3 && (sav.IndeterminateGame || ModifierKeys == Keys.Control))
             {
diff --git a/PKHeX/Legality/Analysis.cs b/PKHeX/Legality/Analysis.cs
index d5b949f58..db7720c7c 100644
--- a/PKHeX/Legality/Analysis.cs
+++ b/PKHeX/Legality/Analysis.cs
@@ -12,8 +12,9 @@ namespace PKHeX.Core
         private readonly List<CheckResult> Parse = new List<CheckResult>();
 
         private List<GBEncounterData> EncountersGBMatch;
-        private object EncounterOriginalGB => EncountersGBMatch?.FirstOrDefault()?.Encounter;
+        private object EncounterOriginalGB;
         private object EncounterMatch;
+        private int EncounterSpecies;
         private Type Type; // Parent class when applicable (EncounterStatic / MysteryGift)
         private Type MatchedType; // Child class if applicable (WC6, PGF, etc)
         private string EncounterName => Legal.getEncounterTypeName(pkm, EncounterOriginalGB ?? EncounterMatch);
@@ -122,13 +123,14 @@ namespace PKHeX.Core
             pkm = pk;
             if (!pkm.IsOriginValid)
             { AddLine(Severity.Invalid, V187, CheckIdentifier.None); return; }
-            
+            UpdateTradebackG12();
             updateEncounterChain();
             updateMoveLegality();
             updateTypeInfo();
             verifyNickname();
             verifyDVs();
             verifyG1OT();
+            verifyMiscG1();
         }
         private void parsePK3(PKM pk)
         {
@@ -212,6 +214,57 @@ namespace PKHeX.Core
             Parse.Add(Encounter);
             EvoChainsAllGens = Legal.getEvolutionChainsAllGens(pkm, EncounterOriginalGB ?? EncounterMatch);
         }
+        private void UpdateTradebackG12()
+        {
+            if (pkm.Format == 1)
+            {
+                if (!Legal.AllowGen1Tradeback)
+                {
+                    pkm.TradebackStatus = TradebackType.Gen1_NotTradeback;
+                    (pkm as PK1).CatchRateIsItem = false;
+                }
+                else
+                {
+                    var catch_rate = (pkm as PK1).Catch_Rate;
+                    // If catch rate match a species catch rate from the evolution chain of the species but do not match a generation 2 item means it was not tradeback
+                    // If match a held item but not a species catch rate then in means it was tradeback
+                    var HeldItemCatchRate = (catch_rate == 0 || Legal.HeldItems_GSC.Any(h => h == catch_rate));
+                    // For species catch rate discart species that have no valid encounters and different catch rate that their preevolutions
+                    var Lineage = Legal.getLineage(pkm).Where(s => !Legal.Species_NotAvailable_CatchRate.Contains(s)).ToList();
+                    var RGBCatchRate = Lineage.Any(s => catch_rate == PersonalTable.RB[s].CatchRate);
+                    // Dragonite Catch Rate is different than Dragonair in Yellow but there is not any Dragonite encounter
+                    var YCatchRate = Lineage.Any(s => s != 149 && catch_rate == PersonalTable.Y[s].CatchRate);
+                    if (HeldItemCatchRate && !RGBCatchRate && !YCatchRate)
+                        pkm.TradebackStatus = TradebackType.WasTradeback;
+                    else if (!HeldItemCatchRate && (RGBCatchRate || YCatchRate))
+                        pkm.TradebackStatus = TradebackType.Gen1_NotTradeback;
+                    else
+                        pkm.TradebackStatus = TradebackType.Any;
+
+                    // Set CatchRateIsItem to true to keep the held item stored when changed species
+                    // only if catch rate match a valid held item and do not match the default catch rate from the species
+                    // If pokemon have not been traded to gen 2 then catch rate could not be a held item
+                    (pkm as PK1).CatchRateIsItem = pkm.Gen1_NotTradeback ? false : (HeldItemCatchRate && !RGBCatchRate && !YCatchRate);
+                }
+            }
+            else if (pkm.Format == 2 || pkm.VC2)
+            {
+                // Eggs, pokemon with non-empty crystal met location and generation 2 species without generation 1 preevolutions can not be traded to generation 1 games
+                if (pkm.IsEgg || pkm.HasOriginalMetLocation || (pkm.Species > Legal.MaxSpeciesID_1 && !Legal.FutureEvolutionsGen1.Contains(pkm.Species)))
+                    pkm.TradebackStatus = TradebackType.Gen2_NotTradeback;
+                else
+                    pkm.TradebackStatus = TradebackType.Any;
+            }
+            else if (pkm.VC1)
+            {
+                // Probably if VC2 is released VC1 pokemon with met date after VC2 Bank release date will be TradebackType.Any
+                pkm.TradebackStatus = TradebackType.Gen1_NotTradeback;
+            }
+            else
+            {
+                pkm.TradebackStatus = TradebackType.Any;
+            }
+        }
         private void updateTypeInfo()
         {
             if (pkm.VC && pkm.Format == 7)
diff --git a/PKHeX/Legality/Checks.cs b/PKHeX/Legality/Checks.cs
index 2c19b3f94..d320c3aff 100644
--- a/PKHeX/Legality/Checks.cs
+++ b/PKHeX/Legality/Checks.cs
@@ -773,7 +773,7 @@ namespace PKHeX.Core
         }
         private CheckResult verifyEncounterG12()
         {
-            EncountersGBMatch = Legal.getEncounter12(pkm, Legal.AllowGBCartEra && pkm.Format < 3);
+            EncountersGBMatch = Legal.getEncounter12(pkm);
             if (EncountersGBMatch == null)
                 return new CheckResult(Severity.Invalid, V80, CheckIdentifier.Encounter);
 
@@ -782,7 +782,7 @@ namespace PKHeX.Core
                 pkm.WasEgg = true;
                 return verifyEncounterEgg();
             }
-            EncounterMatch = EncounterOriginalGB;
+            EncounterMatch = EncounterOriginalGB = EncountersGBMatch?.FirstOrDefault()?.Encounter;
             if (EncounterMatch is EncounterSlot)
                 return new CheckResult(Severity.Valid, V68, CheckIdentifier.Encounter);
             if (EncounterMatch is EncounterStatic)
@@ -2339,6 +2339,64 @@ namespace PKHeX.Core
 
             AddLine(Severity.Valid, V318, CheckIdentifier.Form);
         }
+        private void verifyMiscG1()
+        {
+            if (pkm.Format > 1)
+                return;
+
+            var Type_A = (pkm as PK1).Type_A;
+            var Type_B = (pkm as PK1).Type_B;
+            if (pkm.Species == 137)
+            {
+                // Porygon can have any type combination of any generation 1 species because of the move Conversion,
+                // that change Porygon type to match the oponent types
+                var Type_A_Match = Legal.Types_Gen1.Any(t => t == Type_A);
+                var Type_B_Match = Legal.Types_Gen1.Any(t => t == Type_B);
+                if (!Type_A_Match)
+                    AddLine(Severity.Invalid, V386, CheckIdentifier.Misc);
+                if (!Type_B_Match)
+                    AddLine(Severity.Invalid, V387, CheckIdentifier.Misc);
+                if (Type_A_Match && Type_B_Match)
+                {
+                    var TypesAB_Match = PersonalTable.RB.IsValidTypeCombination(Type_A, Type_B);
+                    if (TypesAB_Match)
+                        AddLine(Severity.Valid, V391, CheckIdentifier.Misc);
+                    else
+                        AddLine(Severity.Invalid, V388, CheckIdentifier.Misc);
+                }
+            }
+            else // Types must match species types
+            {
+                var Type_A_Match = Type_A == PersonalTable.RB[pkm.Species].Types[0];
+                var Type_B_Match = Type_B == PersonalTable.RB[pkm.Species].Types[1];
+                
+                AddLine(Type_A_Match ? Severity.Valid : Severity.Invalid, Type_A_Match ? V392 : V389, CheckIdentifier.Misc);
+
+                AddLine(Type_B_Match ? Severity.Valid : Severity.Invalid, Type_B_Match ? V393 : V390, CheckIdentifier.Misc);
+            }
+            var catch_rate =(pkm as PK1).Catch_Rate;
+            switch (pkm.TradebackStatus)
+            {
+                case TradebackType.Any:
+                case TradebackType.WasTradeback:
+                    if (catch_rate == 0 || Legal.HeldItems_GSC.Any(h => h == catch_rate))
+                    { AddLine(Severity.Valid, V394, CheckIdentifier.Misc); }
+                    else if (pkm.TradebackStatus == TradebackType.WasTradeback)
+                    { AddLine(Severity.Invalid, V395, CheckIdentifier.Misc); }
+                    else
+                        goto case TradebackType.Gen1_NotTradeback;
+                    break;
+                case TradebackType.Gen1_NotTradeback:
+                    if ( ((pkm.Species == 149) && (catch_rate == PersonalTable.Y[149].CatchRate)) ||
+                         (Legal.Species_NotAvailable_CatchRate.Contains(pkm.Species) && (catch_rate == PersonalTable.RB[pkm.Species].CatchRate)))
+                    { AddLine(Severity.Invalid, V396, CheckIdentifier.Misc); }
+                    else if (!EvoChainsAllGens[1].Any(e => catch_rate == PersonalTable.RB[e.Species].CatchRate || catch_rate == PersonalTable.Y[e.Species].CatchRate))
+                    { AddLine(Severity.Invalid, pkm.Gen1_NotTradeback? V397: V399, CheckIdentifier.Misc); }
+                    else
+                    { AddLine(Severity.Valid, V398, CheckIdentifier.Misc); }
+                    break;
+            }
+        }
         private void verifyMisc()
         {
             if (pkm.Format == 7 && ((PK7)pkm).PelagoEventStatus != 0)
@@ -2374,7 +2432,11 @@ namespace PKHeX.Core
                 if (Type == typeof(EncounterStatic))
                 {
                     var enc = EncounterMatch as EncounterStatic;
-                    if (enc.Fateful)
+                    var fateful = enc.Fateful;
+                    if (pkm.Gen3 && pkm.WasEgg && !pkm.IsEgg)
+                        // Fatefull generation 3 eggs lost fatefull mark after hatch
+                        fateful = false;
+                    if (fateful)
                     {
                         if (pkm.FatefulEncounter)
                             AddLine(Severity.Valid, V323, CheckIdentifier.Fateful);
@@ -2508,15 +2570,8 @@ namespace PKHeX.Core
         }
         private CheckResult[] verifyMoves(GameVersion game = GameVersion.Any)
         {
-            int minLvLG1 = 0;
-            if (pkm.GenNumber <= 2)
-                minLvLG1 = pkm.WasEgg ? 6 : (EncounterMatch as IEncounterable)?.LevelMin + 1 ?? 0;
-            var validLevelMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, minLvLG1: minLvLG1, Tutor: false, Machine: false, RemoveTransferHM: false);
-            var validTMHM = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Tutor: false, MoveReminder: false, RemoveTransferHM: false);
-            var validTutor = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Machine: false, MoveReminder: false, RemoveTransferHM: false);
-            Legal.RemoveFutureMoves(pkm, ref validLevelMoves, ref validTMHM, ref validTutor);
             int[] Moves = pkm.Moves;
-            var res = parseMovesForEncounters(game, validLevelMoves, validTMHM, validTutor, Moves);
+            var res = parseMovesForEncounters(game, Moves);
 
             // Duplicate Moves Check
             verifyNoEmptyDuplicates(Moves, res);
@@ -2525,63 +2580,129 @@ namespace PKHeX.Core
 
             return res;
         }
-        private void UptateGen1LevelUpMoves(ref List<int>[] validLevelMoves, List<int> DefaultMoves, int generation)
+        private void UptateGen1LevelUpMoves(ValidEncounterMoves EncounterMoves, int defaultLvlG1, int generation)
         {
-            switch (generation)
+            switch(generation)
             {
                 case 1:
-                    validLevelMoves[1] = Legal.getValidMoves(pkm, EvoChainsAllGens[1], generation: 1, minLvLG1: (EncounterMatch as IEncounterable).LevelMin, LVL: true, Tutor: false, Machine: false, MoveReminder: false).ToList();
-                    break;
                 case 2:
-                    validLevelMoves[1] = DefaultMoves;
+                    var lvlG1 = EncounterMatch == null ? 6 : (EncounterMatch as IEncounterable).LevelMin + 1;
+                    if (lvlG1 != defaultLvlG1)
+                        EncounterMoves.validLevelUpMoves[1] = Legal.getValidMoves(pkm, EvoChainsAllGens[1], generation: 1, minLvLG1: lvlG1, LVL: true, Tutor: false, Machine: false, MoveReminder: false).ToList();
                     break;
             }
+
         }
-        private CheckResult[] parseMovesForEncounters(GameVersion game, List<int>[] validLevelMoves, List<int>[] validTMHM, List<int>[] validTutor, int[] Moves)
+        private ValidEncounterMoves getEncounterValidMoves(int defaultspecies, int encounterspecies, object encounter, int encounterlevel)
+        {
+            var minLvLG1 = pkm.GenNumber <= 2 ? encounterlevel + 1 : 0;
+            // If encounter species is the same species from the first match, the one in variable EncounterMatch, its evolution chains is already in EvoChainsAllGens
+            var EvolutionChains = defaultspecies == EncounterSpecies ? EvoChainsAllGens : Legal.getEvolutionChainsAllGens(pkm, encounter);
+            var LevelMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, minLvLG1: minLvLG1, Tutor: false, Machine: false, RemoveTransferHM: false);
+            var TMHMMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Tutor: false, MoveReminder: false, RemoveTransferHM: false);
+            var TutorMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Machine: false, MoveReminder: false, RemoveTransferHM: false);
+            return new ValidEncounterMoves()
+            {
+                EncounterSpecies = encounterspecies,
+                validLevelUpMoves = LevelMoves,
+                validTMHMMoves = TMHMMoves,
+                validTutorMoves = TutorMoves,
+                EvolutionChains = EvolutionChains,
+                minLvlG1 = minLvLG1
+            };
+        }
+        private List<ValidEncounterMoves> getEncountersValidMoves(List<object> encounters, DexLevel[] vs)
+        {
+            var defaultspecies = Legal.getEncounterSpecies(pkm, vs, EncounterMatch);
+            var r = new List<ValidEncounterMoves>();
+            foreach(DexLevel evo in vs)
+            {
+                // Store only one set of valid moves for species, using the minimun level encounter for that species
+                var encounters_evo = encounters.Where(e => Legal.getEncounterSpecies(pkm, vs, e) == evo.Species);
+                if (!encounters_evo.Any())
+                    continue;
+                // For every possible encounter species get valid moves using minimun encounter level for each species
+                // Generation 1 encounters will overwrite the valid level moves of gen 1 if encounter level is not the minimun
+                var minlevel = encounters_evo.Min(e => Legal.getEncounterLevel(pkm, e));
+                var encounter_minlevel = encounters_evo.First(e => Legal.getEncounterLevel(pkm, e) == minlevel);
+                r.Add(getEncounterValidMoves(defaultspecies, evo.Species, encounter_minlevel, minlevel));
+            }
+            return r;
+        }
+        private CheckResult[] parseMovesForEncounters(GameVersion game, int[] Moves)
         {
             if (pkm.Species == 235) // special handling for Smeargle
-                return parseMovesForSmeargle(Moves, validLevelMoves); // Smeargle can have any moves except a few
+                return parseMovesForSmeargle(Moves); // Smeargle can have any moves except a few
 
             // Gather Encounters
             var encounters = pkm.GenNumber <= 2 ? GetEncounterMovesGBEra() :
                              pkm.GenNumber == 3 && pkm.WasEgg ? GetEncounterMovesGen3Egg() :
                              GetEncounterMoves();
 
+
             // it could be duplicated between EncounterMatch and EncounterStaticMatch or EncounterMatch and EventGiftMatch
             encounters = encounters.Distinct().ToList();
 
             if (!encounters.Any()) // There isn't any valid encounter and wasnt an egg
             {
-                var empty = Legal.GetEmptyMovesList(EvoChainsAllGens);
-                var emptyegg = Legal.GetEmptyEggMovesList();
-                return parseMoves(pkm.Moves, validLevelMoves, pkm.RelearnMoves, validTMHM, validTutor, new int[0], emptyegg, emptyegg, empty, new int[0], new int[0], false);
+                return parseMovesNoEncounters(Moves);
             }
 
             // Iterate over encounters
             bool pre3DS = pkm.GenNumber < 6;
+            var vs = Legal.getValidPreEvolutions(pkm).ToArray();
+            // gather valid moves for encounter species
+            var EncountersMoves = getEncountersValidMoves(encounters, vs);
             CheckResult[] res = new CheckResult[4];
-            var defaultGen1Moves = validLevelMoves[1];
             foreach (var enc in encounters)
             {
                 EncounterMatch = enc;
-                var EncounterMatchGen = EncounterMatch as IGeneration;
-                if (EncounterMatchGen != null)
-                    UptateGen1LevelUpMoves(ref validLevelMoves, defaultGen1Moves, EncounterMatchGen.Generation);
+                if (pkm.GenNumber <= 2)
+                    EncounterOriginalGB = enc;
+               
+                EncounterSpecies = Legal.getEncounterSpecies(pkm, vs, EncounterMatch);
+                var EncounterMoves = EncountersMoves.First(e => e.EncounterSpecies == EncounterSpecies);
+                EvoChainsAllGens = EncounterMoves.EvolutionChains;
+
                 if (pkm.GenNumber <= 3)
-                    pkm.WasEgg = EncounterMatch == null || ((EncounterMatch as IEncounterable)?.EggEncounter ?? false);
+                    pkm.WasEgg = (EncounterMatch == null) || ((EncounterMatch as IEncounterable)?.EggEncounter ?? false);
+
+                var EncounterMatchGen = EncounterMatch as IGeneration;
+                var defaultG1LevelMoves = EncounterMoves.validLevelUpMoves[1];
+                if (EncounterMatchGen != null)
+                    // Generation 1 can have different minimun level in different encounter of the same species, update valid level moves
+                    UptateGen1LevelUpMoves(EncounterMoves, EncounterMoves.minLvlG1, EncounterMatchGen.Generation);
+
                 res = pre3DS
-                    ? parseMovesPre3DS(game, validLevelMoves, validTMHM, validTutor, Moves)
-                    : parseMoves3DS(game, validLevelMoves, validTMHM, validTutor, Moves);
+                    ? parseMovesPre3DS(game, EncounterMoves.validLevelUpMoves, EncounterMoves.validTMHMMoves, EncounterMoves.validTutorMoves, Moves)
+                    : parseMoves3DS(game, EncounterMoves.validLevelUpMoves, EncounterMoves.validTMHMMoves, EncounterMoves.validTutorMoves, Moves);
 
                 if (res.All(x => x.Valid))
                     break;
+
+                if (EncounterMatchGen?.Generation == 1)
+                    // If is not valid restore generation 1 moves
+                    EncounterMoves.validLevelUpMoves[1] = defaultG1LevelMoves;
             }
             return res;
         }
-        private CheckResult[] parseMovesForSmeargle(int[] Moves, List<int>[] validLevelMoves)
+        private CheckResult[] parseMovesNoEncounters(int[] Moves)
+        {
+            EncounterSpecies = pkm.Species;
+            var validLevelMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, minLvLG1: 1, Tutor: false, Machine: false, RemoveTransferHM: false);
+            var validTMHM = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Tutor: false, MoveReminder: false, RemoveTransferHM: false);
+            var validTutor = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, LVL: false, Machine: false, MoveReminder: false, RemoveTransferHM: false);
+            Legal.RemoveFutureMoves(pkm, ref validLevelMoves, ref validTMHM, ref validTutor);
+            
+            var empty = Legal.GetEmptyMovesList(EvoChainsAllGens);
+            var emptyegg = Legal.GetEmptyEggMovesList();
+            return parseMoves(pkm.Moves, validLevelMoves, pkm.RelearnMoves, validTMHM, validTutor, new int[0], emptyegg, emptyegg, empty, new int[0], new int[0], false);
+        }
+        private CheckResult[] parseMovesForSmeargle(int[] Moves)
         {
             if (!pkm.IsEgg)
                 return parseMovesSketch(Moves);
+            var validLevelMoves = Legal.getValidMovesAllGens(pkm, EvoChainsAllGens, minLvLG1: 1, Tutor: false, Machine: false, RemoveTransferHM: false);
             // can only know sketch as egg
             var empty = Legal.GetEmptyMovesList(EvoChainsAllGens);
             var emptyegg = Legal.GetEmptyEggMovesList();
@@ -2716,7 +2837,7 @@ namespace PKHeX.Core
                     Games = new[] { GameVersion.B2W2 };
                     break;
             }
-            var issplitbreed = Legal.SplitBreed.Contains(pkm.Species);
+            var issplitbreed = Legal.getSplitBreedGeneration(pkm).Contains(pkm.Species);
             foreach (var ver in Games)
             {
                 var EventEggMoves = (EncounterMatch as IMoveset)?.Moves ?? new int[0];
@@ -3034,6 +3155,11 @@ namespace PKHeX.Core
                                 // Example: Azurill levelup/tmhm/tutor move, incompatible with Marill egg moves
                                 res[m] = new CheckResult(Severity.Invalid, string.Format(V376, splitbreedspecies0, splitbreedspecies1), CheckIdentifier.Move);
                         }
+                        else if (EncounterMatch == null && !EggMovesSplitLearned[0].Any() && !IncenseMovesLearned.Any())
+                        {
+                            // Day care egg with no incense species exclusive moves, we can assume non-incense egg, that means there is no need to check if evolution from incense species is valid
+                            EncounterSpecies = Legal.getBaseEggSpecies(pkm, 1);
+                        }
                     }
                 }
                 
@@ -3062,7 +3188,7 @@ namespace PKHeX.Core
                     foreach (int m in Gen1MovesLearned)
                         res[m] = new CheckResult(Severity.Invalid, V335, CheckIdentifier.Move);
 
-                if (gen == 1 && pkm.Format == 1 && !Legal.AllowGBCartEra)
+                if (gen == 1 && pkm.Format == 1 && pkm.Gen1_NotTradeback)
                 {
                     // Check moves learned at the same level in red/blue and yellow, illegal because there is no move reminder
                     // Only two incompatibilites and only there are no illegal combination if generation 2 or 7 are included in the analysis
@@ -3083,7 +3209,7 @@ namespace PKHeX.Core
                     return res;
             }
 
-            if (pkm.Species == 292 && (EncounterMatch as IEncounterable)?.Species != 292)
+            if (pkm.Species == 292 && EncounterSpecies != 292)
             {
                 // Ignore Shedinja if the Encounter was also a Shedinja, assume null Encounter as a Nincada egg
                 // Check Shedinja evolved moves from Ninjask after egg moves
@@ -3209,7 +3335,7 @@ namespace PKHeX.Core
             // Ignore if there is an invalid move or an empty move, this validtion is only for 4 non-empty moves that are all valid, but invalid as a 4 combination
             // Ignore Mr.Mime and Sodowodoo from generations 1 to 3, they cant be evolved from Bonsly or Munchlax
             // Ignore if encounter species is the evolution species, pokemon was not evolved by the player
-            if (!res.All(r => r?.Valid ?? false) || moves.Any(m => m == 0) || (Legal.BabyEvolutionWithMove.Contains(pkm.Species) && pkm.GenNumber <= 3) || (EncounterMatch as IEncounterable)?.Species == pkm.Species)
+            if (!res.All(r => r?.Valid ?? false) || moves.Any(m => m == 0) || (Legal.BabyEvolutionWithMove.Contains(pkm.Species) && pkm.GenNumber <= 3) || EncounterSpecies == pkm.Species)
                 return;
 
             // Mr.Mime and Sodowodoo from eggs that does not have any exclusive egg move or level up move from Mime Jr or Bonsly, egg can be assumed to be a non-incense egg, pokemon was not evolved by the player
diff --git a/PKHeX/Legality/Core.cs b/PKHeX/Legality/Core.cs
index 60876b5a0..1c6b57b19 100644
--- a/PKHeX/Legality/Core.cs
+++ b/PKHeX/Legality/Core.cs
@@ -14,6 +14,7 @@ namespace PKHeX.Core
 
         /// <summary>Setting to specify if an analysis should permit data sourced from the physical cartridge era of GameBoy games.</summary>
         public static bool AllowGBCartEra = false;
+        public static bool AllowGen1Tradeback = false;
 
         /// <summary>Setting to specify if the e-berry index item is an eningma berry or a e-reader berry and the name of the e-reader berry</summary>
         public static bool EReaderBerryIsEnigma = true;
@@ -554,6 +555,7 @@ namespace PKHeX.Core
                 MarkEncountersGeneration(ref SlotsRBY, 1);
                 MarkEncountersGeneration(ref StaticRBY, 1);
                 Evolves1 = new EvolutionTree(new[] { Resources.evos_rby }, GameVersion.RBY, PersonalTable.Y, MaxSpeciesID_1);
+                FixPersonalTableY();
             }
             // Gen 2
             {
@@ -758,6 +760,13 @@ namespace PKHeX.Core
             }
         }
 
+        private static void FixPersonalTableY()
+        {
+            // Personal Table from Yellow do not have yellow catch rate for Pikachu and Kadabra, have RedBlue instead
+            PersonalTable.Y[25].CatchRate = 163; // Pikachu
+            PersonalTable.Y[64].CatchRate = 96; // Kadabra
+        }
+
         // Moves
         internal static int[] getMinLevelLearnMove(int species, int Generation, List<int> moves)
         {
@@ -994,7 +1003,7 @@ namespace PKHeX.Core
                     }
                 }
             }
-            else
+            else if (validLevelMoves.Length >= 3)
             {
                 int tradeback = pkm.Format == 2 ? 1 : 2;
                 validLevelMoves[tradeback]?.RemoveAll(x => FutureMoves.Contains(x));
@@ -1227,7 +1236,7 @@ namespace PKHeX.Core
         }
         internal static List<int>[] getBaseEggMoves(PKM pkm, GameVersion gameSource, int lvl)
         {
-            if (SplitBreed.Contains(pkm.Species))
+            if (getSplitBreedGeneration(pkm.GenNumber).Contains(pkm.Species))
                 return new[]
                 {
                      getBaseEggMoves(pkm, 0, gameSource,lvl).ToList(),
@@ -1237,7 +1246,7 @@ namespace PKHeX.Core
         }
         internal static List<int>[] getEggMoves(PKM pkm, GameVersion Version)
         {
-            if (SplitBreed.Contains(pkm.Species))
+            if (getSplitBreedGeneration(pkm.GenNumber).Contains(pkm.Species))
                 return new[]
                 {
                      getEggMoves(pkm, getBaseEggSpecies(pkm, 0), 0, Version).ToList(),
@@ -1388,6 +1397,18 @@ namespace PKHeX.Core
                 if (e.Form != pkm.AltForm && !e.SkipFormCheck && !getCanFormChange(pkm, e.Species))
                     continue;
 
+                if (pkm.Format == 1 && pkm.Gen1_NotTradeback)
+                {
+                    var catch_rate = (pkm as PK1).Catch_Rate;
+                    // Pure gen 1, trades can be filter by catch rate
+                    if ((pkm.Species == 25 || pkm.Species == 26) && catch_rate == 190)
+                        // Red Blue Pikachu, is not a static encounter
+                        continue;
+
+                    if (catch_rate != PersonalTable.RB[e.Species].CatchRate && catch_rate != PersonalTable.Y[e.Species].CatchRate)
+                        continue;
+                }
+
                 // Defer to EC/PID check
                 // if (e.Shiny != null && e.Shiny != pkm.IsShiny)
                     // continue;
@@ -1464,14 +1485,17 @@ namespace PKHeX.Core
         }
         internal static GameVersion[] getGen1GameEncounter(PKM pk)
         {
-            if (pk.Format != 2 || AllowGBCartEra)
+            if (pk.Format != 1 || !pk.Gen1_NotTradeback)
                 return new[] { GameVersion.RD, GameVersion.YW };
             if (25 <= pk.Species && pk.Species <= 26)
                 // Yellow Pikachu detected by its special catch rate
-                return new[] { (((PK1)pk).Catch_Rate == 163) ? GameVersion.YW : GameVersion.RD };
+                return new[] { ((pk as PK1).Catch_Rate == 163) ? GameVersion.YW : GameVersion.RD };
             if (64 <= pk.Species && pk.Species <= 65)
                 // Yellow Kadabra detected by its special catch rate
-                return new[] { (((PK1)pk).Catch_Rate == 96) ? GameVersion.YW : GameVersion.RD };
+                return new[] { ((pk as PK1).Catch_Rate == 96) ? GameVersion.YW : GameVersion.RD };
+            if (148 <= pk.Species && pk.Species <= 149 && ((pk as PK1).Catch_Rate == 27))
+                // Yellow Dragonair detected by its special catch rate, is have another catch rate could be red/blue dratini or yellow dratini
+                return new[] { GameVersion.YW };
             return new[] { GameVersion.RD, GameVersion.YW };
         }
         internal static IEnumerable<int> getInitialMovesGBEncounter(int species, int lvl, GameVersion ver)
@@ -1592,7 +1616,7 @@ namespace PKHeX.Core
         }
         internal static int getRequiredMoveCount(PKM pk, int[] moves, List<int>[] learn, List<int>[] tmhm, List<int>[] tutor, int[] initialmoves)
         {
-            if (pk.Format != 1 || AllowGBCartEra) // No MoveDeleter
+            if (pk.Format != 1 || !pk.Gen1_NotTradeback) // No MoveDeleter
                 return 1; // Move deleter exits, slots from 2 onwards can allways be empty
 
             int required = getRequiredMoveCount(pk, moves, learn, initialmoves);
@@ -1618,20 +1642,22 @@ namespace PKHeX.Core
         private static int getRequiredMoveSlotsRegular(PKM pk, int[] moves, List<int>[] learn, int[] initialmoves)
         {
             int species = pk.Species;
+            int catch_rate = (pk as PK1).Catch_Rate;
             // Caterpie and Metapod evolution lines have different count of possible slots available if captured in different evolutionary phases
             // Example: a level 7 caterpie evolved into metapod will have 3 learned moves, a captured metapod will have only 1 move
-            if (010 == species || species == 011)
+            if ((species == 011 || species == 012) && catch_rate == 120)
             {
-                if (!moves.Any(m => G1MetapodMoves.Contains(m))) // Captured as Metapod without Caterpie moves
-                    return initialmoves.Union(learn[1]).Distinct().Count(lm => lm != 0 && !G1MetapodMoves.Contains(lm));
+                // Captured as Metapod without Caterpie moves
+                return initialmoves.Union(learn[1]).Distinct().Count(lm => lm != 0 && !G1CaterpieMoves.Contains(lm));
+                // There is no valid Butterfree encounter in generation 1 games
             }
-            if (species == 014 || species == 015)
+            if ((species == 014 || species == 015) && (catch_rate == 45 || catch_rate == 120))
             {
-                if (species == 15 && !moves.Any(m => G1KakunaMoves.Contains(m))) // Captured as Beedril without Weedle and Kakuna moves
+                if (species == 15 && catch_rate == 45) // Captured as Beedril without Weedle and Kakuna moves
                     return initialmoves.Union(learn[1]).Distinct().Count(lm => lm != 0 && !G1KakunaMoves.Contains(lm));
 
-                if (!moves.Any(m => G1WeedleMoves.Contains(m))) // Captured as Kakuna without Weedle moves
-                    return initialmoves.Union(learn[1]).Distinct().Count(lm => lm != 0 && !G1WeedleMoves.Contains(lm));
+                // Captured as Kakuna without Weedle moves
+                return initialmoves.Union(learn[1]).Distinct().Count(lm => lm != 0 && !G1WeedleMoves.Contains(lm));
             }
 
             return getRequiredMoveCountSpecies3(species, pk.CurrentLevel, moves) ? 3 : 0; // no match
@@ -1656,6 +1682,7 @@ namespace PKHeX.Core
         }
         private static int getRequiredMoveCountDecrement(PKM pk, int[] moves, List<int>[] learn, int[] initialmoves)
         {
+            int catch_rate = (pk as PK1).Catch_Rate;
             int usedslots = initialmoves.Union(learn[1]).Where(m => m != 0).Distinct().Count();
             // Yellow optional moves, reduce usedslots if the yellow move is not present
             // The count wont go bellow 1 because the yellow moves were already counted and are not the only initial or level up moves
@@ -1672,9 +1699,9 @@ namespace PKHeX.Core
 
             if (064 == pk.Species || pk.Species == 065)
             {
-                if (!moves.Contains(134))// Initial Yellow Kadabra Kinesis 
+                if (catch_rate != 100)// Initial Yellow Kadabra Kinesis (move 134)
                     usedslots--;
-                if (pk.CurrentLevel < 10 && !moves.Contains(50)) // Kadabra Disable, not learned until 20 if captured as Abra
+                if (catch_rate == 200 && pk.CurrentLevel < 20) // Kadabra Disable, not learned until 20 if captured as Abra (move 50)
                     usedslots--;
             }
             if (104 == pk.Species || pk.Species == 105) // Cubone and Marowak
@@ -1741,7 +1768,8 @@ namespace PKHeX.Core
             switch (gameSource)
             {
                 case GameVersion.RBY:
-                    return getValidEncounterTradeVC1(pkm, p, TradeGift_RBY);
+                    var table = !AllowGen1Tradeback ? TradeGift_RBY_NoTradeback : TradeGift_RBY_Tradeback;
+                    return getValidEncounterTradeVC1(pkm, p, table);
                 case GameVersion.GSC:
                     return getValidEncounterTradeVC2(pkm, p);
                 default:
@@ -1750,13 +1778,8 @@ namespace PKHeX.Core
         }
         private static EncounterTrade getValidEncounterTradeVC2(PKM pkm, DexLevel[] p)
         {
-            // Check RBY trades with loosened level criteria.
-            var z = getValidEncounterTradeVC1(pkm, p, TradeGift_RBY_2);
-            if (z != null)
-                return z;
-
             // Check GSC trades. Reuse generic table fetch-match
-            z = getValidEncounterTradeVC1(pkm, p, TradeGift_GSC);
+            var z = getValidEncounterTradeVC1(pkm, p, TradeGift_GSC);
 
             // Filter Criteria
             if (z?.Gender != pkm.Gender)
@@ -1781,12 +1804,19 @@ namespace PKHeX.Core
                 return null;
             if (z.Level > pkm.CurrentLevel) // minimum required level
                 return null;
+            if(pkm.Format == 1 && pkm.Gen1_NotTradeback)
+            {
+                // Even if the in game trade use the tables with source pokemon allowing generaion 2 games, the traded pokemon could be a non-tradeback pokemon
+                var catch_rate = (pkm as PK1).Catch_Rate;
+                if (catch_rate != PersonalTable.RB[z.Species].CatchRate && catch_rate != PersonalTable.Y[z.Species].CatchRate)
+                    return null;
+            }
             return z;
         }
         private static GBEncounterData getEncounter12(PKM pkm, GameVersion game)
         {
             var gen = game == GameVersion.GSC ? 2 : 1;
-            bool WasEgg = game == GameVersion.GSC && getWasEgg23(pkm) && !NoHatchFromEgg.Contains(pkm.Species);
+            bool WasEgg = !pkm.Gen1_NotTradeback && game == GameVersion.GSC && getWasEgg23(pkm) && !NoHatchFromEgg.Contains(pkm.Species);
             if (WasEgg)
             {
                 // Further Filtering
@@ -1835,10 +1865,10 @@ namespace PKHeX.Core
                 return new GBEncounterData(pkm, gen, t);
             return null;
         }
-        internal static List<GBEncounterData> getEncounter12(PKM pkm, bool gen2)
+        internal static List<GBEncounterData> getEncounter12(PKM pkm)
         {
-            var g1 = pkm.IsEgg || pkm.HasOriginalMetLocation ? null : getEncounter12(pkm, GameVersion.RBY);
-            var g2 = gen2 ? getEncounter12(pkm, GameVersion.GSC) : null;
+            var g1 = pkm.Gen2_NotTradeback ? null : getEncounter12(pkm, GameVersion.RBY);
+            var g2 = pkm.Gen1_NotTradeback ? null : getEncounter12(pkm, GameVersion.GSC);
             if (g1 == null && g2 == null)
                 return null;
             if (g1 == null || g2 == null)
@@ -2591,9 +2621,10 @@ namespace PKHeX.Core
         internal static DexLevel[][] getEvolutionChainsAllGens(PKM pkm, object Encounter)
         {
             var CompleteEvoChain = getEvolutionChain(pkm, Encounter).ToArray();
-            int size = Math.Max(pkm.Format, 2);
-            DexLevel[][] GensEvoChains = new DexLevel[size + 1][];
-            for (int i = 0; i <= size; i++)
+            int maxgen = pkm.Format == 1 && !pkm.Gen1_NotTradeback ? 2 : pkm.Format;
+            int mingen = pkm.Format == 2 && !pkm.Gen2_NotTradeback ? 1 : pkm.GenNumber;
+            DexLevel[][] GensEvoChains = new DexLevel[maxgen + 1][];
+            for (int i = 0; i <= maxgen; i++)
                 GensEvoChains[i] = new DexLevel[0];
 
             if (pkm.Species == 0 || pkm.Format > 2 && pkm.GenU) // Illegal origin or empty pokemon, return only chain for current format
@@ -2611,15 +2642,13 @@ namespace PKHeX.Core
             }
 
             int lvl = pkm.CurrentLevel;
-            int maxgen = pkm.Format <= 2 ? 2 : pkm.Format;
-            int mingen = pkm.VC2 || pkm.Format <= 2 ? 1 : pkm.GenNumber;
 
             // Iterate generations backwards because level will be decreased from current level in each generation
             for (int gen = maxgen; gen >= mingen; gen--)
             {
-                if ((pkm.Gen1 || pkm.VC1) && pkm.Format > 2 && 2 <= gen && gen <= 6)
+                if (pkm.GenNumber == 1 && pkm.Gen1_NotTradeback && gen == 2)
                     continue;
-                if ((pkm.Gen2 || pkm.VC2) && 3 <= gen && gen <= 6)
+                if (pkm.GenNumber <= 2 && 3 <= gen && gen <= 6)
                     continue;
                 if (!pkm.HasOriginalMetLocation && pkm.Format > 2 && gen < pkm.Format && gen <= 4 && lvl > pkm.Met_Level)
                 {
@@ -2660,6 +2689,10 @@ namespace PKHeX.Core
                     //For example a gen3 charizar in format 7 with current level 36 and met level 36
                     //chain level for charmander is 35, is bellow met level
                     GensEvoChains[gen] = GensEvoChains[gen].Where(e => e.Level >= getMinLevelGeneration(pkm,gen)).ToArray();
+
+                if (gen == 1 && GensEvoChains[gen].LastOrDefault()?.Species > MaxSpeciesID_1)
+                    // Remove generation 2 pre-evolutions
+                    GensEvoChains[gen] = GensEvoChains[gen].Take(GensEvoChains[gen].Length - 1).ToArray();
             }
             return GensEvoChains;
         }
@@ -2913,6 +2946,26 @@ namespace PKHeX.Core
             // Get Valid levels
             IEnumerable<DexLevel> vs = getValidPreEvolutions(pkm, maxspeciesorigin: maxspeciesorigin, lvl: ignoreLevel ? 100 : -1, skipChecks:ignoreLevel);
 
+            bool IsRGBKadabra = false;
+            if (pkm.Format == 1 && pkm.Gen1_NotTradeback)
+            {
+                // Pure gen 1, slots can be filter by catch rate
+                if ((pkm.Species == 25 || pkm.Species == 26) && (pkm as PK1).Catch_Rate == 163)
+                    // Yellow Pikachu, is not a wild encounter
+                    return slotdata;
+                if ((pkm.Species == 64 || pkm.Species == 65) && (pkm as PK1).Catch_Rate == 96)
+                    // Yellow Kadabra, ignore Abra encounters
+                    vs = vs.Where(s => s.Species == 64);
+                if ((pkm.Species == 148 || pkm.Species == 149) && (pkm as PK1).Catch_Rate == 27)
+                    // Yellow Dragonair, ignore Dratini encounters
+                    vs = vs.Where(s => s.Species == 148);
+                else
+                {
+                    IsRGBKadabra = (pkm.Species == 64 || pkm.Species == 65) && (pkm as PK1).Catch_Rate == 100;
+                    vs = vs.Where(s => (pkm as PK1).Catch_Rate == PersonalTable.RB[s.Species].CatchRate);
+                }
+            }
+
             // Get slots where pokemon can exist
             bool ignoreSlotLevel = ignoreLevel;
             IEnumerable<EncounterSlot> slots = loc.Slots.Where(slot => vs.Any(evo => evo.Species == slot.Species && (ignoreSlotLevel || evo.Level >= slot.LevelMin - df)));
@@ -2931,7 +2984,11 @@ namespace PKHeX.Core
                 encounterSlots = slots.Where(slot => slot.LevelMin <= lvl).ToList();
 
             if (gen <= 2)
-            {   
+            {
+                if (IsRGBKadabra)
+                    //Red Kadabra slots : Level 49 and 51 in RGB, but level 20 and 27 in Yellow
+                    encounterSlots = encounterSlots.Where(slot => slot.LevelMin >= 49).ToList();
+
                 // For gen 1 and 2 return Minimum level slot
                 // Minimum level is needed to check available moves, because there is no move reminder in gen 1,
                 // There are moves in the level up table that cant be legally obtained
@@ -3031,7 +3088,24 @@ namespace PKHeX.Core
             }
             return slotLocations;
         }
-        private static IEnumerable<DexLevel> getValidPreEvolutions(PKM pkm, int maxspeciesorigin = -1, int lvl = -1, bool skipChecks = false)
+        internal static int getEncounterLevel(PKM pkm, object encounter)
+        {
+            return (encounter as IEncounterable[])?.Min(e => e.LevelMin) ??
+                   (encounter as IEncounterable)?.LevelMin ??
+                   (pkm.GenNumber <= 3 ? 5 : 1 ); //egg
+        }
+        internal static int getEncounterSpecies(PKM pkm, DexLevel[] vs, object encounter)
+        {
+            if (encounter is int)
+                return (int)encounter;
+            if (encounter is IEncounterable[])
+                return vs.Reverse().First(s => ((IEncounterable[])encounter).Any(slot => slot.Species == s.Species)).Species;
+            if (encounter is IEncounterable)
+                return vs.Reverse().First(s => ((IEncounterable)encounter).Species == s.Species).Species;
+            // encounter is null, is an egg or invalid origin, return base species
+            return vs.Last().Species;
+        }
+        internal static IEnumerable<DexLevel> getValidPreEvolutions(PKM pkm, int maxspeciesorigin = -1, int lvl = -1, bool skipChecks = false)
         {
             if (lvl < 0)
                 lvl = pkm.CurrentLevel;
@@ -3046,8 +3120,10 @@ namespace PKHeX.Core
                     new DexLevel { Species = 292, Level = lvl, MinLevel = 20 },
                     new DexLevel { Species = 290, Level = lvl-1, MinLevel = 1 }
                 };
+            if (maxspeciesorigin == -1 && pkm.InhabitedGeneration(2) && pkm.GenNumber == 1)
+                maxspeciesorigin = MaxSpeciesID_2;
 
-            var et = getEvolutionTable(pkm);
+            var et = maxspeciesorigin == MaxSpeciesID_2 ? getEvolutionTable(2) : getEvolutionTable(pkm);
             return et.getValidPreEvolutions(pkm, lvl: lvl, maxSpeciesOrigin: maxspeciesorigin, skipChecks: skipChecks);
         }
         private static IEnumerable<EncounterStatic> getStatic(PKM pkm, IEnumerable<EncounterStatic> table, int maxspeciesorigin =-1, int lvl = -1)
diff --git a/PKHeX/Legality/LegalityCheckStrings.cs b/PKHeX/Legality/LegalityCheckStrings.cs
index 7f4d04993..db49da2fb 100644
--- a/PKHeX/Legality/LegalityCheckStrings.cs
+++ b/PKHeX/Legality/LegalityCheckStrings.cs
@@ -63,6 +63,11 @@ namespace PKHeX.Core
         public static string V372 { get; set; } = "{0} Berry";
         public static string V380 { get; set; } = "Encounter Type match encounter.";
         public static string V382 { get; set; } = "Encounter Type not implemented for pokemon encounter.";
+        public static string V391 { get; set; } = "Porygon with valid Type A and B values.";
+        public static string V392 { get; set; } = "Valid Type A, match species type.";
+        public static string V393 { get; set; } = "Valid Type B, match species type.";
+        public static string V394 { get; set; } = "Catch rate match a valid held item from generation 2";
+        public static string V398 { get; set; } = "Catch Rate match a species from pokemon evolution chain.";
         #endregion
 
         #region Legality Check Result Strings
@@ -374,6 +379,15 @@ namespace PKHeX.Core
         public static string V379 {get; set;} = "{0} Inherited Move. Incompatible with {1} inherited moves.";
         public static string V381 {get; set;} = "Encounter Type does not match encounter.";
         public static string V385 {get; set;} = "Moves combinations is not compatible with {0} evolution.";
+        public static string V386 {get; set;} = "Porygon with invalid Type A value.";
+        public static string V387 {get; set;} = "Porygon with invalid Type B value.";
+        public static string V388 {get; set;} = "Porygon with invalid Type A and B values. Does not a match a valid type combination.";
+        public static string V389 {get; set;} = "Invalid Type A, does not match species type.";
+        public static string V390 {get; set;} = "Invalid Type B, does not match species type.";
+        public static string V395 {get; set;} = "Catch rate does not match a valid held item from generation 2";
+        public static string V396 {get; set;} = "Catch rate match species without encounters. Expected a preevolution catch rate.";
+        public static string V397 {get; set;} = "Catch rate does not match any species from pokemon evolution chain.";
+        public static string V399 {get; set;} = "Catch rate does not match any species from pokemon evolution chain or any generation 2 held items.";
         #endregion
 
     }
diff --git a/PKHeX/Legality/Structures/TradebackType.cs b/PKHeX/Legality/Structures/TradebackType.cs
new file mode 100644
index 000000000..02d28c12f
--- /dev/null
+++ b/PKHeX/Legality/Structures/TradebackType.cs
@@ -0,0 +1,10 @@
+namespace PKHeX.Core
+{
+    public enum TradebackType
+    {
+        Any,
+        Gen1_NotTradeback,
+        Gen2_NotTradeback,
+        WasTradeback
+    }
+}
diff --git a/PKHeX/Legality/Structures/ValidEncounterMoves.cs b/PKHeX/Legality/Structures/ValidEncounterMoves.cs
new file mode 100644
index 000000000..2eb6e9655
--- /dev/null
+++ b/PKHeX/Legality/Structures/ValidEncounterMoves.cs
@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace PKHeX.Core
+{
+    public class ValidEncounterMoves
+    {
+        public int EncounterSpecies { get; set; }
+        public DexLevel[][] EvolutionChains { get; set; }
+        public List<int>[] validLevelUpMoves { get; set; }
+        public List<int>[] validTMHMMoves { get; set; }
+        public List<int>[] validTutorMoves { get; set; }
+        public int minLvlG1 { get; set; }
+    }
+}
diff --git a/PKHeX/Legality/Tables1.cs b/PKHeX/Legality/Tables1.cs
index 9eab37f8e..3b31230ee 100644
--- a/PKHeX/Legality/Tables1.cs
+++ b/PKHeX/Legality/Tables1.cs
@@ -112,70 +112,63 @@ namespace PKHeX.Core
             new EncounterStatic { Species = 054, Level = 15, Moves = new [] { 133, 10 }, Version = GameVersion.Stadium }, // Stadium Psyduck (Amnesia)
             new EncounterStatic { Species = 151, Level = 5, IVs = new [] {15,15,15,15,15,15}, Version = GameVersion.VCEvents }, // Event Mew
         };
-        internal static readonly EncounterTrade[] TradeGift_RBY =
-        {
+        internal static readonly EncounterTrade[] TradeGift_RBY_Common =
+          {
             // Species & Minimum level (legal) possible to acquire at.
           //new EncounterTrade { Species = 122, Generation = 1, Level = 06 }, // Mr. Mime - Game Corner Abra
             new EncounterTrade { Species = 032, Generation = 1, Level = 02 }, // Nidoran♂ - Wild Nidoran♀
             new EncounterTrade { Species = 029, Generation = 1, Level = 02 }, // Nidoran♀ - Wild Nidoran♂
             new EncounterTrade { Species = 030, Generation = 1, Level = 16 }, // Nidorina - Evolve Nidorino
             new EncounterTrade { Species = 108, Generation = 1, Level = 15 }, // Lickitung - Surf Slowbro
-            new EncounterTrade { Species = 124, Generation = 1, Level = 15 }, // Jynx - Fish Poliwhirl (GSC: 10)
             new EncounterTrade { Species = 083, Generation = 1, Level = 02 }, // Farfetch’d - Wild Spearow
             new EncounterTrade { Species = 101, Generation = 1, Level = 03 }, // Electrode - Wild Raichu
-            new EncounterTrade { Species = 114, Generation = 1, Level = 13 }, // Tangela - Wild Venonat (GSC: 5)
-            new EncounterTrade { Species = 086, Generation = 1, Level = 28 }, // Seel - Wild Ponyta (GSC: 6)
             
             new EncounterTrade { Species = 122, Generation = 1, Level = 03 }, // Mr. Mime - Wild Jigglypuff
             new EncounterTrade { Species = 060, Generation = 1, Level = 02 }, // Poliwag - Wild Rattata
+          //new EncounterTrade { Species = 083, Generation = 1, Level = 02 }, // Farfetch’d - Wild Pidgey
+            new EncounterTrade { Species = 079, Generation = 1, Level = 22 }, // Slowpoke - Wild Seel
+            
+            new EncounterTrade { Species = 051, Generation = 1, Level = 15 }, // Dugtrio - Trade Lickitung
+            new EncounterTrade { Species = 047, Generation = 1, Level = 13 }, // Parasect - Trade Tangela
+        };
+        internal static readonly EncounterTrade[] TradeGift_RBY_NoTradeback = TradeGift_RBY_Common.Concat(new[]
+        {
+            // Species & Minimum level (legal) possible to acquire at.
+            new EncounterTrade { Species = 124, Generation = 1, Level = 15 }, // Jynx - Fish Poliwhirl (GSC: 10)
+            new EncounterTrade { Species = 114, Generation = 1, Level = 13 }, // Tangela - Wild Venonat (GSC: 5)
+            new EncounterTrade { Species = 086, Generation = 1, Level = 28 }, // Seel - Wild Ponyta (GSC: 6)
+            
             new EncounterTrade { Species = 115, Generation = 1, Level = 42 }, // Kangaskhan - Evolve Rhydon (GSC: 30)
             new EncounterTrade { Species = 128, Generation = 1, Level = 28 }, // Tauros - Evolve Persian (GSC: 18)
             new EncounterTrade { Species = 093, Generation = 1, Level = 20 }, // Haunter - Trade Machoke (GSC: 10)
-          //new EncounterTrade { Species = 083, Generation = 1, Level = 02 }, // Farfetch’d - Wild Pidgey
             new EncounterTrade { Species = 075, Generation = 1, Level = 16 }, // Graveler - Evolve Kadabra (GSC: 15)
-            new EncounterTrade { Species = 079, Generation = 1, Level = 22 }, // Slowpoke - Wild Seel
             new EncounterTrade { Species = 098, Generation = 1, Level = 15 }, // Krabby - Wild Growlithe (GSC: 5)
             
           //new EncounterTrade { Species = 122, Generation = 1, Level = 08 }, // Mr. Mime - Wild Clefairy (GSC: 6)
             new EncounterTrade { Species = 067, Generation = 1, Level = 20 }, // Machoke - Wild Cubone (GSC: 10)
-            new EncounterTrade { Species = 051, Generation = 1, Level = 15 }, // Dugtrio - Trade Lickitung
-            new EncounterTrade { Species = 047, Generation = 1, Level = 13 }, // Parasect - Trade Tangela
             new EncounterTrade { Species = 112, Generation = 1, Level = 15 }, // Rhydon - Surf Golduck (GSC: 10)
             new EncounterTrade { Species = 087, Generation = 1, Level = 15 }, // Dewgong - Wild Growlithe (GSC: 5)
             new EncounterTrade { Species = 089, Generation = 1, Level = 25 }, // Muk - Wild Kangaskhan (GSC: 14)
-        };
-        internal static readonly EncounterTrade[] TradeGift_RBY_2 =
+        }).ToArray();
+        internal static readonly EncounterTrade[] TradeGift_RBY_Tradeback = TradeGift_RBY_Common.Concat(new[]
         {
             // Trade gifts that can be obtained at a lower level due to the requested Pokémon being a lower level in GSC
-          //new EncounterTrade { Species = 122, Generation = 1, Level = 06 }, // Mr. Mime - Game Corner Abra
-          //new EncounterTrade { Species = 032, Generation = 1, Level = 02 }, // Nidoran♂ - Wild Nidoran♀
-          //new EncounterTrade { Species = 029, Generation = 1, Level = 02 }, // Nidoran♀ - Wild Nidoran♂
-          //new EncounterTrade { Species = 030, Generation = 1, Level = 16 }, // Nidorina - Evolve Nidorino
-          //new EncounterTrade { Species = 108, Generation = 1, Level = 15 }, // Lickitung - Surf Slowbro
             new EncounterTrade { Species = 124, Generation = 1, Level = 10 }, // Jynx - Fish Poliwhirl (RBY: 15)
-          //new EncounterTrade { Species = 083, Generation = 1, Level = 02 }, // Farfetch’d - Wild Spearow
-          //new EncounterTrade { Species = 101, Generation = 1, Level = 03 }, // Electrode - Wild Raichu
             new EncounterTrade { Species = 114, Generation = 1, Level = 05 }, // Tangela - Wild Venonat (RBY: 13)
             new EncounterTrade { Species = 086, Generation = 1, Level = 05 }, // Seel - Egg Ponyta (RBY: 28)
             
-          //new EncounterTrade { Species = 122, Generation = 1, Level = 03 }, // Mr. Mime - Wild Jigglypuff
-          //new EncounterTrade { Species = 060, Generation = 1, Level = 02 }, // Poliwag - Wild Rattata
             new EncounterTrade { Species = 115, Generation = 1, Level = 30 }, // Kangaskhan - Evolve Rhydon (RBY: 42)
             new EncounterTrade { Species = 128, Generation = 1, Level = 18 }, // Tauros - Evolve Persian (RBY: 28)
             new EncounterTrade { Species = 093, Generation = 1, Level = 10 }, // Haunter - Trade Machoke (RBY: 20)
-          //new EncounterTrade { Species = 083, Generation = 1, Level = 02 }, // Farfetch’d - Wild Pidgey
             new EncounterTrade { Species = 075, Generation = 1, Level = 15 }, // Graveler - Evolve Kadabra (RBY: 16)
-          //new EncounterTrade { Species = 079, Generation = 1, Level = 22 }, // Slowpoke - Wild Seel
             new EncounterTrade { Species = 098, Generation = 1, Level = 05 }, // Krabby - Egg Growlithe (RBY: 15)
             
           //new EncounterTrade { Species = 122, Generation = 1, Level = 08 }, // Mr. Mime - Wild Clefairy (RBY: 6)
             new EncounterTrade { Species = 067, Generation = 1, Level = 05 }, // Machoke - Egg Cubone (RBY: 20)
-          //new EncounterTrade { Species = 051, Generation = 1, Level = 15 }, // Dugtrio - Trade Lickitung
-          //new EncounterTrade { Species = 047, Generation = 1, Level = 13 }, // Parasect - Trade Tangela
             new EncounterTrade { Species = 112, Generation = 1, Level = 10 }, // Rhydon - Surf Golduck (RBY: 15)
             new EncounterTrade { Species = 087, Generation = 1, Level = 05 }, // Dewgong - Egg Growlithe (RBY: 15)
             new EncounterTrade { Species = 089, Generation = 1, Level = 05 }, // Muk - Egg Kangaskhan (RBY: 25)
-        };
+        }).ToArray();
         internal static readonly EncounterArea FishOldGood_RBY = new EncounterArea { Location = -1, Slots = new EncounterSlot[]
         {
             new EncounterSlot1 {Species = 129, LevelMin = 05, LevelMax = 05, Type = SlotType.Old_Rod,  Rate = -1, }, // Magikarp
@@ -197,5 +190,13 @@ namespace PKHeX.Core
         {
             25, 26, 29, 30, 31, 32, 33, 34, 36, 38, 40, 59, 91, 103, 114, 121,
         };
+        internal static readonly int[] Types_Gen1 =
+        {
+            0, 1, 2, 3, 4, 5, 7, 8, 20, 21, 22, 23, 24, 25, 26
+        };
+        internal static readonly int[] Species_NotAvailable_CatchRate =
+        {
+            12, 18, 31, 34, 36, 38, 45, 53, 59, 62, 65, 68, 71, 76, 78, 91, 94, 103, 121
+        };
     }
 }
diff --git a/PKHeX/PKHeX.Core.csproj b/PKHeX/PKHeX.Core.csproj
index 9c463e72a..60b211d6f 100644
--- a/PKHeX/PKHeX.Core.csproj
+++ b/PKHeX/PKHeX.Core.csproj
@@ -175,6 +175,8 @@
     <Compile Include="Legality\Structures\Nature.cs" />
     <Compile Include="Legality\Structures\PIDIV.cs" />
     <Compile Include="Legality\Structures\SlotType.cs" />
+    <Compile Include="Legality\Structures\TradebackType.cs" />
+    <Compile Include="Legality\Structures\ValidEncounterMoves.cs" />
     <Compile Include="Legality\Tables.cs" />
     <Compile Include="Legality\Tables2.cs" />
     <Compile Include="Legality\Tables1.cs" />
diff --git a/PKHeX/PKM/PK1.cs b/PKHeX/PKM/PK1.cs
index d62c40727..7282a4592 100644
--- a/PKHeX/PKM/PK1.cs
+++ b/PKHeX/PKM/PK1.cs
@@ -141,12 +141,11 @@ namespace PKHeX.Core
             get { return PKX.getG1Species(Data[0]); }
             set
             {
-                int currentRate = PersonalInfo.CatchRate;
                 Data[0] = (byte)PKX.setG1Species(value);
 
                 // Before updating catch rate, check if non-standard
-                if (Catch_Rate == currentRate)
-                    Catch_Rate = PersonalInfo.CatchRate;
+                if (!CatchRateIsItem)
+                    Catch_Rate = PersonalTable.RB[Legal.getBaseSpecies(this)].CatchRate;
                 Type_A = PersonalInfo.Types[0];
                 Type_B = PersonalInfo.Types[1];
             }
@@ -273,6 +272,7 @@ namespace PKHeX.Core
         public override int CNT_Tough { get { return 0; } set { } }
         public override int CNT_Sheen { get { return 0; } set { } }
         #endregion
+        public bool CatchRateIsItem = false;
 
         public PK2 convertToPK2()
         {
diff --git a/PKHeX/PKM/PKM.cs b/PKHeX/PKM/PKM.cs
index b8ca0d8dd..d33782662 100644
--- a/PKHeX/PKM/PKM.cs
+++ b/PKHeX/PKM/PKM.cs
@@ -310,7 +310,8 @@ namespace PKHeX.Core
                 if (Gen3) return 3;
                 if (Gen2) return Format; // 2
                 if (Gen1) return Format; // 1
-                if (VC) return 1;
+                if (VC1) return 1;
+                if (VC2) return 2;
                 return -1;
             } 
         }
@@ -435,6 +436,9 @@ namespace PKHeX.Core
         }
 
         // Legality Extensions
+        public TradebackType TradebackStatus { get; set; } = TradebackType.Any;
+        public bool Gen1_NotTradeback => TradebackStatus == TradebackType.Gen1_NotTradeback;
+        public bool Gen2_NotTradeback => TradebackStatus == TradebackType.Gen2_NotTradeback;
         public virtual bool WasLink => false;
         private bool _WasEgg;
         public virtual bool WasEgg
@@ -517,9 +521,6 @@ namespace PKHeX.Core
             if (Format == Generation)
                 return true;
 
-            if (Format < Generation)
-                return false; // Future
-
             if (!IsOriginValid)
                 return false;
 
@@ -527,11 +528,22 @@ namespace PKHeX.Core
             if (Legal.getMaxSpeciesOrigin(GenNumber) < species && !Legal.getFutureGenEvolutions(GenNumber).Contains(species))
                 return false;
 
+            // Trade generation 1 -> 2 
+            if (Format == 2 && Generation == 1 && !Gen2_NotTradeback)
+                return true;
+
+            // Trade generation 2 -> 1 
+            if (Format == 1 && Generation == 2 && !Gen1_NotTradeback)
+                return true;
+
+            if (Format < Generation)
+                return false; // Future
+
             int gen = GenNumber;
             switch (Generation)
             {
-                case 1:
-                case 2: return Format <= 2 || VC;
+                case 1: return Format == 1 || VC1;
+                case 2: return Format == 2 || VC2;
                 case 3: return Gen3;
                 case 4: return 3 <= gen && gen <= 4;
                 case 5: return 3 <= gen && gen <= 5;
diff --git a/PKHeX/PersonalInfo/PersonalTable.cs b/PKHeX/PersonalInfo/PersonalTable.cs
index 9aec81298..3883242cd 100644
--- a/PKHeX/PersonalInfo/PersonalTable.cs
+++ b/PKHeX/PersonalInfo/PersonalTable.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 
 namespace PKHeX.Core
 {
@@ -180,5 +181,9 @@ namespace PKHeX.Core
             }
             return result;
         }
+        public bool IsValidTypeCombination(int Type1, int Type2)
+        {
+            return Table.Any(p => p.Types[0] == Type1 && p.Types[1] == Type2);
+        }
     }
 }
diff --git a/PKHeX/Resources/text/en/LegalityCheckStrings_en.txt b/PKHeX/Resources/text/en/LegalityCheckStrings_en.txt
index ca3bc4830..759da4af2 100644
--- a/PKHeX/Resources/text/en/LegalityCheckStrings_en.txt
+++ b/PKHeX/Resources/text/en/LegalityCheckStrings_en.txt
@@ -35,6 +35,11 @@ V362 = Default move in generation {0}.
 V372 = {0} Berry
 V380 = Encounter Type match encounter.
 V382 = Encounter Type not implemented for pokemon encounter.
+V391 = Porygon with valid Type A and B values.
+V392 = Valid Type A, match species type.
+V393 = Valid Type B, match species type.
+V394 = Catch rate match a valid held item from generation 2.
+V398 = Catch Rate match any species from pokemon evolution chain.
 V203 = Genderless Pokémon should not have a gender.
 V201 = Encryption Constant is not set.
 V204 = Held item is unreleased.
@@ -315,4 +320,13 @@ V377 = Egg Move. Not expected in a gift egg.
 V378 = Inherited move learned by Level-up. Not expected in a gift egg.
 V379 = {0} Inherited Move. Incompatible with {1} inherited moves.
 V381 = Encounter Type does not match encounter.
-V385 = Moves combinations is not compatible with {0} evolution.
\ No newline at end of file
+V385 = Moves combinations is not compatible with {0} evolution.
+V386 = Porygon with invalid Type A value.
+V387 = Porygon with invalid Type B value.
+V388 = Porygon with invalid Type A and B values. Does not a match a valid type combination.
+V389 = Invalid Type A, does not match species type.
+V390 = Invalid Type B, does not match species type.
+V395 = Catch rate does not match a valid held item from generation 2.
+V396 = Catch rate match species without encounters. Expected a preevolution catch rate.
+V397 = Catch rate does not match any species from pokemon evolution chain.
+V399 = Catch rate does not match any species from pokemon evolution chain or any generation 2 held items.
\ No newline at end of file
diff --git a/PKHeX/Resources/text/ko/LegalityCheckStrings_ko.txt b/PKHeX/Resources/text/ko/LegalityCheckStrings_ko.txt
index 5e4344db5..ebed5ff74 100644
--- a/PKHeX/Resources/text/ko/LegalityCheckStrings_ko.txt
+++ b/PKHeX/Resources/text/ko/LegalityCheckStrings_ko.txt
@@ -35,6 +35,12 @@ V362 = {0}세대 기본 기술입니다.
 V372 = {0}열매
 V380 = Encounter Type match encounter.
 V382 = Encounter Type not implemented for pokemon encounter.
+V382 = Encounter Type not implemented for pokemon encounter.
+V391 = Porygon with valid Type A and B values.
+V392 = Valid Type A, match species type.
+V393 = Valid Type B, match species type.
+V394 = Catch rate match a valid held item from generation 2.
+V398 = Catch rate match any species from pokemon evolution chain.
 V203 = 무성 포켓몬은 성별을 가질 수 없습니다.
 V201 = 암호화 상수가 설정되어 있지 않습니다.
 V204 = 지닌 물건이 배포되지 않은 물건입니다.
@@ -314,4 +320,13 @@ V377 = 자력기입니다. 이벤트 알에서 예상된 기술이 아닙니다.
 V378 = 유전받은 레벨업 기술입니다. 이벤트 알에서 예상된 기술이 아닙니다.
 V379 = 유전받은 {0} 기술입니다. 유전받은 {1} 기술과 함께 존재할 수 없습니다.
 V381 = Encounter Type does not match encounter.
-V385 = Moves combinations is not compatible with {0} evolution.
\ No newline at end of file
+V385 = Moves combinations is not compatible with {0} evolution.
+V386 = Porygon with invalid Type A value.
+V387 = Porygon with invalid Type B value.
+V388 = Porygon with invalid Type A and B values. Does not a match a valid type combination.
+V389 = Invalid Type A, does not match species type.
+V390 = Invalid Type B, does not match species type.
+V395 = Catch rate does not match a valid held item from generation 2.
+V396 = Catch rate match species without encounters. Expected a preevolution catch rate.
+V397 = Catch rate does not match any species from pokemon evolution chain.
+V399 = Catch rate does not match any species from pokemon evolution chain or any generation 2 held items.
\ No newline at end of file
diff --git a/PKHeX/Resources/text/zh/LegalityCheckStrings_zh.txt b/PKHeX/Resources/text/zh/LegalityCheckStrings_zh.txt
index 7fab0bbde..c483ec371 100644
--- a/PKHeX/Resources/text/zh/LegalityCheckStrings_zh.txt
+++ b/PKHeX/Resources/text/zh/LegalityCheckStrings_zh.txt
@@ -35,6 +35,12 @@ V362 = 在第{0}世代的默认招式。
 V372 = {0}树果
 V380 = Encounter Type match encounter.
 V382 = Encounter Type not implemented for pokemon encounter.
+V382 = Encounter Type not implemented for pokemon encounter.
+V391 = Porygon with valid Type A and B values.
+V392 = Valid Type A, match species type.
+V393 = Valid Type B, match species type.
+V394 = Catch rate match a valid held item from generation 2
+V398 = Catch rate match any species from pokemon evolution chain.
 V203 = 无性别宝可梦不能有性别。
 V201 = 未设置加密常数。
 V204 = 持有物未解禁。
@@ -314,4 +320,13 @@ V377 = 遗传招式。礼物蛋不应有。
 V378 = 遗传升级招式。礼物蛋不应有。
 V379 = {0}的遗传招式。与遗传的招式{1}不共存。
 V381 = Encounter Type does not match encounter.
-V385 = Moves combinations is not compatible with {0} evolution.
\ No newline at end of file
+V385 = Moves combinations is not compatible with {0} evolution.
+V386 = Porygon with invalid Type A value.
+V387 = Porygon with invalid Type B value.
+V388 = Porygon with invalid Type A and B values. Does not a match a valid type combination.
+V389 = Invalid Type A, does not match species type.
+V390 = Invalid Type B, does not match species type.
+V395 = Catch rate does not match a valid held item from generation 2.
+V396 = Catch rate match species without encounters. Expected a preevolution catch rate.
+V397 = Catch rate does not match any species from pokemon evolution chain.
+V399 = Catch rate does not match any species from pokemon evolution chain or any generation 2 held items.
\ No newline at end of file