Invasion

Invasion is an Unreal Tournament 2004 gametype, played on Deathmatch maps. It features human players who have to defend themselves against incoming waves of monsters from Unreal, earning points by killing these monsters.

Monsters on the enemy team include: Flies, Mantas, Pupae, Gasbags, Krall, Skaarj, and Warlords. None of the Return to Na Pali monsters appear.

When the game begins, the human team gets some time to gather weapons, ammo, and other power-ups. After a count-down, the first wave of monsters appears, spawning at regular player starts. When all monsters have been killed, the count-down immediately restarts, giving players the chance to restock, after which the next, stronger wave comes. The monster configuration can be changed by the server's administrator, but generally Invasion starts with only weak monster, with stronger monsters appearing in the later waves. Higher difficulty levels also make monsters faster. This process repeats until the human team is defeated.

Once killed, a player cannot respawn until the current round has ended. If all players are killed, the game ends.

It is possible to play Invasion with the Instagib mutator, removing a large part of the challenge because the Instagib Rifle kills even the stronger enemies with just one shot. However, relatively weak enemies such as the Fly will now pose a greater thread due to their small size, which makes them hard to hit with the thin beam.

Fans have created custom maps with fortified areas designed to let players be able to defend themselves better. Invasion-inspired mods have also been created.