diff --git a/asm/macros/battle_script.inc b/asm/macros/battle_script.inc
index cf2045eb6f..2498bce64e 100644
--- a/asm/macros/battle_script.inc
+++ b/asm/macros/battle_script.inc
@@ -1946,9 +1946,10 @@
 	various \battler, VARIOUS_CLEAR_SHELL_TRAP
 	.endm
 
-	.macro checkshelltrap battler:req, ptr:req
+	.macro checkshelltrap battler:req, ptr1:req, ptr2:req
 	various \battler, VARIOUS_CHECK_SHELL_TRAP
-	.4byte \ptr
+	.4byte \ptr1
+	.4byte \ptr2
 	.endm
 
 @ helpful macros
diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index d5d5707ff5..e453e37056 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -413,7 +413,7 @@ gBattleScriptsForMoveEffects::
 	.4byte BattleScript_EffectShellTrap               @ EFFECT_SHELL_TRAP
 
 BattleScript_EffectShellTrap::
-	checkshelltrap BS_ATTACKER, BattleScript_MoveEnd
+	checkshelltrap BS_ATTACKER, BattleScript_ShellTrapExplode, BattleScript_MoveEnd
 	clearshelltrap BS_ATTACKER
 	attackcanceler
 	attackstring
diff --git a/include/battle.h b/include/battle.h
index fbeb3ffb17..ad79240176 100644
--- a/include/battle.h
+++ b/include/battle.h
@@ -153,12 +153,13 @@ struct ProtectStruct
     u32 usedCustapBerry:1;    // also quick claw
     u32 touchedProtectLike:1;
     // End of 32-bit bitfield
-    u8 disableEjectPack:1;
-    u8 statFell:1;
-    u8 pranksterElevated:1;
-    u8 quickDraw:1;
-    u8 beakBlastCharge:1;
-    u8 shellTrap:1;
+    u16 disableEjectPack:1;
+    u16 statFell:1;
+    u16 pranksterElevated:1;
+    u16 quickDraw:1;
+    u16 beakBlastCharge:1;
+    u16 shellTrapSet:1;
+    u16 shellTrapTriggered:1;
     u32 physicalDmg;
     u32 specialDmg;
     u8 physicalBattlerId;
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index 31a2d4fc6a..aa3c85375f 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -1543,7 +1543,8 @@ static void Cmd_attackcanceler(void)
         gBattleCommunication[MISS_TYPE] = B_MSG_PROTECTED;
         gBattlescriptCurrInstr++;
     }
-    else if (gProtectStructs[gBattlerTarget].beakBlastCharge && IsMoveMakingContact(gCurrentMove, gBattlerAttacker))
+    else if ((gProtectStructs[gBattlerTarget].beakBlastCharge || gProtectStructs[gBattlerTarget].shellTrapSet)
+             && IsMoveMakingContact(gCurrentMove, gBattlerAttacker))
     {
         gProtectStructs[gBattlerAttacker].touchedProtectLike = TRUE;
         gBattlescriptCurrInstr++;
@@ -4983,7 +4984,7 @@ static void Cmd_moveend(void)
                     effect = 1;
                 }
                 // Not strictly a protect effect, but works the same way
-                else if (gProtectStructs[gBattlerTarget].beakBlastCharge 
+                else if (gProtectStructs[gBattlerTarget].beakBlastCharge
                          && CanBeBurned(gBattlerAttacker)
                          && !(gMoveResultFlags & MOVE_RESULT_NO_EFFECT))
                 {
@@ -4993,6 +4994,21 @@ static void Cmd_moveend(void)
                     gBattlescriptCurrInstr = BattleScript_BeakBlastBurn;
                     effect = 1;
                 }
+                else if (gProtectStructs[gBattlerTarget].shellTrapSet
+                         && !TestSheerForceFlag(gBattlerAttacker, gCurrentMove)
+                         && !(gMoveResultFlags & MOVE_RESULT_NO_EFFECT))
+                {
+                    u32 temp;
+                    gProtectStructs[gBattlerTarget].shellTrapTriggered = TRUE;
+                    gProtectStructs[gBattlerAttacker].touchedProtectLike = FALSE;
+                    // Swap battlers so target attacks attacker with Shell Trap
+                    SWAP(gBattlerAttacker, gBattlerTarget, temp);
+                    // Set current move to Shell Trap
+                    gCurrentMove = MOVE_SHELL_TRAP;
+                    BattleScriptPushCursor();
+                    gBattlescriptCurrInstr = BattleScript_EffectShellTrap;
+                    effect = TRUE;
+                }
             }
             gBattleScripting.moveendState++;
             break;
@@ -9387,10 +9403,24 @@ static void Cmd_various(void)
         }
     }
     case VARIOUS_SET_BEAK_BLAST:    
-        gProtectStructs[gBattlerAttacker].beakBlastCharge = 1;
+        gProtectStructs[gBattlerAttacker].beakBlastCharge = TRUE;
         break;
     case VARIOUS_SET_SHELL_TRAP:
-        gProtectStructs[gBattlerAttacker].shellTrap = 1;
+        gProtectStructs[gBattlerAttacker].shellTrapSet = TRUE;
+        break;
+	case VARIOUS_CLEAR_SHELL_TRAP:
+        gProtectStructs[gBattlerAttacker].shellTrapSet = FALSE;
+        break;
+	case VARIOUS_CHECK_SHELL_TRAP:
+        // Attack with Shell Trap
+        if (gProtectStructs[gBattlerAttacker].shellTrapSet == TRUE && gProtectStructs[gBattlerAttacker].shellTrapTriggered == TRUE)
+            gBattlescriptCurrInstr = T1_READ_PTR(gBattlescriptCurrInstr + 3);
+        // Attacked with Shell Trap, go to move end
+        else if (gProtectStructs[gBattlerAttacker].shellTrapSet == FALSE && gProtectStructs[gBattlerAttacker].shellTrapTriggered == TRUE)
+            gBattlescriptCurrInstr = T1_READ_PTR(gBattlescriptCurrInstr + 7);
+        // Shell Trap failed
+        else
+            gBattlescriptCurrInstr += 11;
         break;
     case VARIOUS_SWAP_SIDE_STATUSES:
     {
diff --git a/src/data/battle_moves.h b/src/data/battle_moves.h
index bf591dac41..62c0595a61 100644
--- a/src/data/battle_moves.h
+++ b/src/data/battle_moves.h
@@ -10218,7 +10218,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT] =
         .accuracy = 100,
         .pp = 5,
         .secondaryEffectChance = 0,
-        .target = MOVE_TARGET_OPPONENTS_FIELD,
+        .target = MOVE_TARGET_BOTH,
         .priority = -3,
         .flags = FLAG_PROTECT_AFFECTED | FLAG_KINGS_ROCK_AFFECTED,
         .split = SPLIT_SPECIAL,