Slayer Pro is a custom Multiplayer gametype in which all players start with a MA5B Assault Rifle or M6D Pistol in the original version, and grenades with no motion sensors, and the game goes to 25 kills. The gametype is loosely based on the official MLG settings. Slayer pro is only playable on Halo: Combat Evolved and Halo: Reach. However, in Halo 2, the default number of kills on regular slayer is 25 in matchmaking on Xbox Live. When you play it you can exercise for single player and multiplayer or just have some fun.