diff --git a/PKHeX/Legality/Tables3.cs b/PKHeX/Legality/Tables3.cs
index e1bbe5e6c..82a669b6b 100644
--- a/PKHeX/Legality/Tables3.cs
+++ b/PKHeX/Legality/Tables3.cs
@@ -274,12 +274,77 @@ public static partial class Legal
         #region AltSlots
         private static readonly EncounterArea[] SlotsRSEAlt =
         {
+            // Swarm can be passed from one game to another via mixing records, that means emerald swarms can occurs in r/s and r/s swarms in emerald
+            // Ruby and Sapphire Swarm
+            new EncounterArea {
+                Location = 17, // Route 102
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 283, LevelMin = 3, LevelMax = 3, Type = SlotType.Grass}, // Surskit
+                },},
+            new EncounterArea {
+                Location = 29, // Route 114
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 283, LevelMin = 15, LevelMax = 15, Type = SlotType.Grass}, // Surskit
+                },},
+            new EncounterArea {
+                Location = 31, // Route 116
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 300, LevelMin = 15, LevelMax = 15, Type = SlotType.Grass}, // Skitty
+                },},
+            new EncounterArea {
+                Location = 32, // Route 117
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 283, LevelMin = 15, LevelMax = 15, Type = SlotType.Grass}, // Surskit
+                },},
+            new EncounterArea {
+                Location = 35, // Route 120
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 283, LevelMin = 28, LevelMax = 28, Type = SlotType.Grass}, // Surskit
+                },},
+
+            //Emerald Swarm
+            new EncounterArea {
+                Location = 17, // Route 102
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 273, LevelMin = 3, LevelMax = 3, Type = SlotType.Grass}, // Seedot
+                },},
+            new EncounterArea {
+                Location = 29, // Route 114
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 274, LevelMin = 15, LevelMax = 15, Type = SlotType.Grass}, // Nuzleaf
+                },},
+            new EncounterArea {
+                Location = 31, // Route 116
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 300, LevelMin = 8, LevelMax = 8, Type = SlotType.Grass}, // Skitty
+                },},
+            new EncounterArea {
+                Location = 32, // Route 117
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 273, LevelMin = 13, LevelMax = 13, Type = SlotType.Grass}, // Seedot
+                },},
+            new EncounterArea {
+                Location = 35, // Route 120
+                Slots = new[]
+                {
+                    new EncounterSlot { Species = 273, LevelMin = 25, LevelMax = 25, Type = SlotType.Grass}, // Seedot
+                },},
+            //Feebas fishing spot
             new EncounterArea {
                 Location = 34, // Route 119
                 Slots = new[]
                 {
-                    new EncounterSlot { Species = 349, LevelMin = 20, LevelMax = 25, Type = SlotType.Super_Rod, Form = 25 }, // Feebas
-                },}
+                    new EncounterSlot { Species = 349, LevelMin = 20, LevelMax = 25, Type = SlotType.Super_Rod } // Feebas
+                },},
         };
         private static readonly EncounterArea[] SlotsFRLGAlt =
         {