Chain Reaction is a multiplayer game mode in Resistance 3. In this mode, the Chimera has to activate the transformers while the humans have to destroy it. The center of the map is the most heated part of the battlefield. One person has to deactivate the transformer while others have to defend him as it has a countdown. You can also keep aside the objectives and kill the enemies in this mode. Killing 50 enemies are more than enough to drain the other team and win the battle.

Resistance Multiplayer Game Modes
Resistance: Fall of Man Deathmatch | Team Deathmatch | Capture the Flag | Meltdown | Assault | Breach | Skirmish
Resistance 2 Deathmatch | Team Deathmatch | Core Control | Meltdown | Skirmish
Resistance: Retribution Deathmatch | Team Deathmatch | Containment | Capture the Flag | Assimilation
Resistance 3 Team Deathmatch | Chain Reaction | Deathmatch | Breach | Capture the Flag | War Games | Invasion
Resistance: Burning Skies Deathmatch | Team Deathmatch | Survival