User blog comment:Callofduty4/Modern Warfare 3 Weapon Proficiency and Equipment trailer/@comment-1647479-20111027232057/@comment-1630756-20111028003708


 * Team Deathmatch is from Doom
 * IW engines 1 and 2's code first originated from the Quake engine
 * Most games use some form of the Unreal III engine
 * Modern Shooter idea from CS

Just because you come up with an idea doesn't mean it's yours. If it did then there'd be patents on everything. (Well, even more than there are now anyways.)