Why Didn't Thief Work in This Situation?

I usedThiefwith myKrookodileand it was powered up by theDark Gem, which should’ve been used, leaving room to steal the opponent’s Maractus’s Life Orb or Leftovers, but I got no item in return during battle! (I’m not wondering why it didn’t have the item after battle; I soon found out.) Please help me on why this would happen- maybe thief only works if you have no item at all in the turn you use it?

~Thanx!

Pleaselog inorregisterto add a comment.

Thief only steals an item if the user is not holding an item itself. If your Krookodile was holding an item, Maractus' item would not replace your Krookodile’s.

Also, on the DB page for Thief, it says:

Thief deals damage and steals the target’s held item, if the user is not holding an item.Items stolen from wild Pokémon are kept after the battle ends, but items stolen from a Trainer’s Pokémon are not. Items stolen from the player’s Pokémon either by wild Pokémon or Trainer Pokémon are returned at the end of the battle. All held items in wi-fi/linked battles (including Battle Tower/Subway/Maison) are returned to their respective owners at the end of a battle.

What ended up happening is that your game didn’t recognize that you lost your Dark Gem because it was the same turn it was used up.