Save 5 people besieged by zombies.

Kill 50 human enemies.

Infected 13 times (lifetime)

Complete the sixth mission of the U.S.S. campaign.

Complete the fifth mission of the U.S.S. campaign.

Kill an infected teammate with a headshot before they become a zombie in any mode.

Complete the fourth mission of the U.S.S. campaign.

Fully upgrade an ability.

Kill 5 enemies while using a zombie as a shield.

Kill 5 enemies with Blood Frenzy in a single campaign game or multiplayer match.

Witness the beginning of the Raccoon City outbreak.

Reached a total of 20,000 or more Camaraderie.

Complete 25 quests while playing with at least one co-op partner.