It took a third night of playing the Call of Duty 4 Beta for everything to sink in, but it's pretty much official: they know what the fuck they're doing. A shooter can't merely be great to come out this holiday, and even amazing might be insufficient. To go against the previously described fucking unstoppable media phalanx - to say nothing of Halo 3 itself, whose multiplayer offering is so broad on every axis that it must be called round - you need to drop something that be off the cheazy.

There are shooters that play with progression to varying degrees. Battlefield 2142 does, but the infantry experience is one part of a whole. Rainbow Six: Vegas does, but its reward scheme is largely cosmetic in nature, and takes place outside of the game proper - between rounds, in austere menus. CoD4's leveling has the sharp inhalation of a WoW ding. It takes place right there at the moment you earn the XP from a kill, with an onscreen celebration of the fact. The reward structure earns you new playmodes, new weapons, new slottable abilities, the right to build custom classes, the right to wear a clan tag. You don't need to wait long to earn them, the schedule is not cruel, but you need to put in your dues. It's not an onerous process: in order to level up, you must simply play Call of Duty 4. Trust me when I say this is something you will want to do.