The UK Clan Carnage League runs what are possibly the largest Team Deathmatch
competitions in the world.
Each week throughout the year approximately 150 clans strive to kick each other's collective butts in Quake 2 and Quake 3 Arena.
Socio-cultural note: Whilst it seems to be that 1 on 1 competition is the main focus in the US in the UK it is more the clan competitions that get the attention. PGL/CPL please take note :) (Like they're gonna read this).