Titanfall features three classes of Titan chassis. At this time, there are only three Titans, each with their own strengths, weaknesses, and core ability.
The default Titan is the Atlas, while the remaining two—the Ogre and the Stryder—must be unlocked in order to be used.
To unlock the Stryder chassis, you must first complete the IMC or the Militia multiplayer campaign. For the Ogre chassis, both campaigns must be completed. It's as simple as that.
Additionally, you will not have to unlock either chassis each time you move from one generation (prestige) to the next. Once they're unlocked, they're unlocked for good.
