- Actor Allusion: Three members of the squad are played by actors from Firefly, including Buck (who's voiced by Nathan Fillion), and they occasionally give a Shout-Out to the show in rare dialog.
- Casting Gag: Buck and Dare are ex-lovers who end up working together—as are their voice actors Nathan Fillion and Tricia Helfer.
- Follow the Leader: "Firefight" mode is Halo's version of Gears of War's "Horde" mode, which many other shooter games have also adopted.
- Working Title: Halo 3: Recon. The original trailer featured that title before being changed to ODST. According to Marty O'Donnell, the switch was made because Ubisoft reneged on letting them use it; they owned the Ghost Recon licensed trademark.
Trivia / Halo 3: ODST