Multiplayer modes are Deathmatch, Team Deathmatch, Tourney, Capture the Flag, Arena CTF and DeadZone. Players at QuakeCon reported the multiplayer gameplay to include elements similar to those in previous Quake games such as strafe-jumping or rocket jumping. Notable additions to play are the ability to send shots through the teleporters and the advancement of the game physics provided by the new technology including the ability to bounce grenades and napalm fire off of jump-pads.
Like the previous Quake games, the multiplayer has a client-server architecture. The network code has been altered from Doom 3, allowing for larger numbers of players on each server; Doom 3 has a four-player restriction, whereas Quake 4 has a standard 16 player limit.
Movement
The player movement in Quake 4 is similar to that in Quake III Arena and Quake Live, but with the additions of ramp jumping and crouch slides. Crouch slides give players the ability to maintain speed by sliding around corners. Ramp jumps allow players to gain extra height from jumping as they reach the top of an inclined object, which while present in the original Quake and Quake II was not included in Quake III Arena.
Plot
The Quake 4 single player mode continues the story of Quake II by pitting the player against a cyborg alien race known as the Strogg. The game follows the story of a Marine Corporal named Matthew Kane who is joining the elite Rhino Squad. Following the success of the protagonist of Quake II in destroying the Strogg's leader, the Makron, Rhino Squad is tasked with spearheading the mission to secure the aliens' home planet Stroggos. In the course of the invasion, the squad ship is shot down and crashes in the middle of a battle zone, separating Kane from his companions. Kane rejoins his scattered team members and partakes in the assault against the Strogg.
After performing a number of tasks, such as destroying and capturing Strogg aircraft hangars and defense systems, Kane and his remaining squad members make it to the USS Hannibal. There they are given their next mission: infiltrating one of the Strogg's central communication hubs, the Tetranode, with an electromagnetic pulse bomb in the hope that it will put the main Strogg Nexus in disarray. Kane is tasked with defending the mission convoy, which takes heavy casualties. After many setbacks, including the destruction of the EMP device by a Strogg ambush, Kane is left to complete the mission, assisted only by Private Johann Strauss (Peter Stormare) and Lance Corporal Nikolai "Sledge" Slidjonovitch (Dimitri Diatchenko). Strauss figures out a way to destroy the core by shutting down its coolant systems. As Kane reaches the entrance to the Tetranode, however, he is greeted by two rocket-equipped network guardians, as well as the newly constructed Makron, which easily defeats Kane and knocks him unconscious.
When Kane awakens, he finds himself strapped to a conveyor belt in the Strogg "Medical Facilities", a structure used for turning those captured and killed by the aliens either into protein food or additional Strogg units. In a long and gruesome first-person cutscene, Kane is taken through this "stroggification" process which violently replaces much of his anatomy with bio-mechanical parts. Before the final controlling neurochip implanted in his brain can be activated, though, Rhino Squad bursts into the facility and rescues Kane. After escaping through the Strogg medical facility and Waste Disposal plant, fighting off zombie-like half-stroggified humans along the way, Kane is forced to combat his former commander, Lieutenant Voss (Michael Gannon), who has been fully stroggified into a powerful mechanized monster but retains his own consciousness long enough to warn Kane. After defeating this threat, Kane and the remaining marines finally make it back to the Hannibal.
The commanders realize that Kane's Strogg physiology has opened up new possibilities for defeating the Strogg, as he can be used to infiltrate locations and teleportation areas previously impenetrable and/or fatally harmful to human forces. The new plan is to directly target the Strogg Nexus Core, a huge centralized brain-like structure which controls the alien forces. The Marines are tasked with infiltrating the three data towers adjacent to the Nexus: Data Storage, Processing, and Networking. There, they will deactivate the Nexus' shield and power up the teleporter used to access the Nexus and send Kane in. Once inside, Kane will travel to the center of the Nexus to destroy the Core Brain and its guardian.
