Multiplayer first person shooter games for PC/Windows with 6-player support

Starship Troopers: Extermination

Players: 0 local, 16 online

Duke Nukem 3D Megaton Edition

Players: 0 local, 8 online

Duke Nukem 3D: 20th Anniversary Edition World Tour

Players: 0 local, 8 online

Tom Clancy's Rainbow Six 3: Raven Shield

Players: 0 local, 0 online

Serious Sam: The First Encounter

Players: 4 local, 16 online

Killing Floor 2

Players: 0 local, 6 online

Unfortunate Spacemen

Players: 0 local, 10 online

Serious Sam 2

Players: 4 local, 6 online

Quake

Players: 0 local, 16 online

Serious Sam: The Second Encounter

Players: 0 local, 16 online

Contagion

Players: 2 local, 8 online

Killing Floor

Players: 0 local, 6 online

Synergy (HL2 mod)

Players: 0 local, 16 online

Starship Troopers

Players: 0 local, 8 online

Team Fortress 2

Players: 0 local, 6 online

DOOM 3: Last Man Standing (Mod)

Players: 0 local, 16 online

Mission Against Terror

Players: 0 local, 8 online

Judge Dredd: Dredd vs. Death

Players: 0 local, 2 online

AirBuccaneers

Players: 0 local, 16 online

Combat Arms

Players: 0 local, 8 online

Serious Sam HD: The First Encounter

Players: 0 local, 16 online

Star Trek Elite Force 2 (HZM Co-op Script Mod)

Players: 0 local, 12 online

Call of Duty: Black Ops

Players: 0 local, 6 online

Serious Sam HD: The Second Encounter

Players: 0 local, 16 online

Gunscape

Players: 8 local, 8 online