No game out there without multiplayer ever last. Even the single players, they might be good for a while, but after a while, it's dead. That's why Perfect Dark has a Single player that you can spend months on, and a multiplayer you can spend forever on. Simulant Bots are the newest thing to hit First Person Shooters. The N64 is the only game coming out with bots being in FTP's.
Bots are computer controlled units.
That means, if you play mutiplayer with 4 friends, you can add 1-8 bots in and you will have a total of 12 people to battle in there. There are many different type of bots, each with it's own attitude, what it would do, and how it would react. The worst sim available. NormalSim The average sim. This sim is pretty smart.