Mutator

A Mutator is a kind of mini-mod that can be applied to games in the Unreal series. Although, compared to conventional mods, changes made to the game are small, mutators can have a large impact on gameplay. For instance Instagib is sometimes considered a whole new gametype.

Unreal Tournament

 * Arena: Replaces every weapon and ammo pickup in the match with one of these, depending on which one is selected:
 * Pulse Arena - Pulse Guns and Pulse Cells
 * Flak Arena - Flak Cannons and Flak Ammo
 * Rocket Launcher Arena - Rocket Launchers and Rocket Packs
 * Shock Rifle Arena - Shock Rifles and Shock Cores
 * Sniper Rifle Arena - Sniper Rifles and Bullet Boxes
 * Impact Hammer Arena - Impact Hammers (*)
 * Minigun Arena - Miniguns and Mini Ammo (*)
 * Instagib DM - Instagib Shock Rifles (**)
 * Jump Match - Enables players to jump extremely high.
 * Low Gravity - Reduces the gravity of the map.
 * Chainsaw Melee - The Impact Hammer is replaced by a Chainsaw.
 * No Redeemer - Redeemers are removed from the map.
 * No Powerups - Invisibility, Shield Belt, Damage Amplifier, Jump Boots and the Big Keg O'Health are removed from the map.
 * Stealth - Everyone is invisible.
 * FatBoy - Frag a lot, and your head grows. Be fragged a lot, and your head shrinks.
 * Instant Rockets - The Rocket Launcher won't fire 6 rockets, but one rocket at a time.
 * Relics - (Bonus Pack 1) Add a relic to the map. This relic spawns in a random place in the map, and disappears after a certain time if nobody picked it up. It's possible to have several of them at once, but the player(s) can carry just one at the same time.
 * Relic: Defense - Prevents 60% of all damage sustained by the user.
 * Relic: Redemption - Prevents it's user from being fragged. It only works once.
 * Relic: Regeneration - Gives 10 HP to it's user every second.
 * Relic: Speed - Increases it's user's speed and air control reflexes.
 * Relic: Strength - Increases it's user's damage output.
 * Relic: Vengeance - When it's user dies, a big skull appears above him. It then explodes like a Redeemer.
 * Team Beacon - (Bonus Pack 2) Your teammates have an arrow above their heads, so you can identify them.
 * Volatile Ammo - (Bonus Pack 2) Ammo explodes when hit by a weapon.
 * Volatile Weapon - (Bonus Pack 2) Weapons are discharged when a player dies.

Unreal Championship/Unreal Tournament 2003/Unreal Tournament2004

 * Air Control - (2003, 2004) Changes how players move in the air.
 * Arena - (UC, 2003, 2004) Replaces weapons and ammo in map.
 * BigHead - (UC, 2003, 2004) See Unreal Tournament section above.
 * Big Wheels - (2004) ONS/AS only. Kill a lot, and your vehicle's wheels grow in size. Be killed a lot, and they'll shrink.
 * Bonus Combos - (2003 Epic BP, 2004) Adds the Pint-sized (LLLL) and Camouflage (RRRR) Adrenaline Combos.
 * Competition Mode - (UC) Disables Species specific attributes and levels the field to everyone. It's the inverse to Species Statistics.
 * Floaty Cadavers - (UC, 2003) Cadavers don't fall to the floor, but float.
 * Game Speed - (2004) Modifies the game's speed.
 * InstaGib - (2003, 2004) See Unreal Tournament section above.
 * Lightning Guns - (2004) Replaces all Sniper Rifles with Lightning Guns.
 * Lightweight Vehicles - (2004) ONS/AS only. When being hit, vehicles will fly higher and farther like balloons.
 * Link Gun Medic - (UC) The Link Gun heals teammates.
 * LowGrav - (UC, 2003, 2004) See Unreal Tournament section above.
 * No Adrenaline - (UC, 2003, 2004) Adrenaline pickups are removed from the map.
 * No Superweapons - (2003, 2004) Redeemers and Ion Painters are removed from the map. In 2004, the Target Painter is removed as well.
 * Onslaught Weapons - (2004) Adds ONS weapons (Mine Layer, Grenade Launcher, AVRiL and Target Painter) to the other gametypes.
 * QuadJump - (2003, 2004) Players can jump up to 4 times instead of 2.
 * Regeneration - (UC, 2003, 2004) All players regenerate health.
 * Slow Enemy - (UC) Reduces the enemy's speed.
 * Slow Motion Corpses - (UC, 2003, 2004) Dramatic slow-mo death animations
 * Sniper Rifles - (2004) Same as Lightning Guns, but inverted: LG are replaced by SR.
 * Species Statistics - (2004) Each race has unique combat statistics.
 * Stunt Vehicles - (2004) ONS/AS only. Vehicles can jump. Hold down the crouch key to charge up and then release to jump. They can also control wheeled vehicles in mid-air.
 * Super Berserk - (2004) Weapons are insanely fast and powerful.
 * UDamage Reward - (2004) Any remaining UDamage powerup is thrown from players when they are fragged.
 * UT Classic - (2004) Classic UT style weapons and movement options.
 * UT2003 Style - (2004) UT2003 style fast weapon switching and boost dodging.
 * UTV2004S - (2004) Required to support UTV2004 SeeAll mode.
 * Vampire - (UC, 2003, 2004) Damaging your opponents will regenerate your health.
 * Vehicle Arena - (2004) ONS/AS only. Replaces all vehicles in a map with a particular one.
 * Zoom InstaGib - (2003, 2004) Same as Instagib, but the secondary fire is a zoom function.