Trailer
From Halopedia, the Halo wiki
Template:Ratings An Announcement Trailer is often used by gaming companies to introduce new games into the public view. These trailers are often pre-rendered (Meaning they do not show actual gameplay footage, but rather a cinematic) and filled with action in order to excite the fans.
Bungie has released Announcement Trailers for Halo: Combat Evolved, Halo 2, and Halo 3. Its most common choice of where to release these videos is at E3. Ensemble Studios released an announcement trailer for Halo Wars.
Note that these trailers are sometimes created in the midst of game development, so, quite often, footage seen in the trailer is modified in the final game, or changed altogether. Because of this, it is sometimes difficult to consider the information in the announcement trailer as canon.
