The Dumdum bullet (Japanese: "ダムダム弾") was an item planned to be used in the original Resident Evil. While the expanding bullet failed to make it into the game, the avatar was reused for the Magnum ammunition. It was to be used with the Colt Python. In early versions of the game, the ammunition can be found with the aid of editing data values or using a cheat device.
The altered rounds did less damage than the standard rounds against many B.O.W.s, but increased damage to Zombies and some bosses. In all future versions of the game, attempting to spawn these rounds in an inventory slot fails, and creating a Magnum pre-loaded with them instead loads the new Beretta from Resident Evil: The Director's Cut.
"Dumdum" is an informal name for an expanding bullet, a bullet designed to expand on impact to increase its damage.