Slayer Pro is a custom Multiplayer gametype in which all players start with a Battle Rifle or M6D Pistol in the original version, and grenades with no Motion trackers, 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. However, in Halo 2, the default number of kills on regular slayer is 25 in matchmaking on Xbox Live. When the player plays it he or she can exercise for single player and multiplayer or just have some fun.
 Tips on Playing
Having no motion tracker in Halo makes things much harder, especially when playing with good players. When you get into a firefight, throw your grenades. Try to get them close, but behind your opponent. Chances are that they are more concerned with hitting you/finding cover than to think about where your grenades have fallen. If their shield is down, the grenade will kill them. If not it will take their shield down making it easier for you to kill them. When using the Battle Rifle, aim for the head and torso. Because it is burst fire, you get several shots in one area. If you hit them in the chest you maximize the damage; with the help of recoil, you could hit them in the head causing even more damage. It is also playable in the Halo: Reach Beta, but you spawn with DMRs and Magnums.