* FanNickname: R'tas Vadum (the Elite counterpart to Lord Hood) is also known by fans as "Half-Jaw," because, well, [[ExactlyWhatItSaysOnTheTin you know]]...
* TheOtherDarrin: Miranda Keyes had her voice actress changed from Creator/JulieBenz to Justis Bolding.
* WhatCouldHaveBeen: The level Cortana went through several iterations. In one version, Cortana would pilot a damaged Scarab to battle the Gravemind while the Chief would fight off Flood boarders. In another, the Chief would pass through the Mausoleum of the Arbiter and fight a ton of infected Arbiters.
** Halo 2 was originally to have ended where Halo 3's first half left off (the portal to the Ark was the Ark itself), making much of the campaign filler and resulting in a relatively story-cramped installment.