Keep your team alive through the suicide mission

Complete Mass Effect 2 twice, or complete it once with a character imported from Mass Effect 1

Use the Omega 4 Relay

Hack a geth collective

Successfully shut down the rogue VI in Project Overlord

Gain the loyalty of the biotic Convict

Gain the loyalty of the Assassin

Gain the loyalty of the thief

Gain the loyalty of the mercenary ("Cerberus Pack" downloadable content)

Confront the Shadow Broker

Kill enemies with 5 different heavy weapons during the game

Gain the loyalty of the krogan

Gain the loyalty of the Professor