these worn spots when the dinosaur becomes enraged, when it charges, it should hit the spikes. After the T. rex smashes into something, it takes a moment to gather its wits. So run away and then turn back to face it. Lure it back across the arena toward one of the damaging surfaces. Then repeat the process: shoot to max out the rex's rage meter, wait for the charge, do the adrenaline dodge (Left or Right + Crouch), wait for the two targeting reticules converge and then shoot. Each time the T. rex charges and bangs its head, it will lose a bit more health until finally the last successful dodge-and-shoot maneuver triggers a second interactive cut scene (described below). IMPORTANT: If you do not complete the adrenaline dodge tutorial with the bear at the beginning of the City of Vilcabamba level it may result in a bug later on in the game, in which the maneuver does not work correctly during the T. rex and subsequent boss fights. See that walkthrough for more info. ALTERNATE STRATEGIES: I strongly recommend learning and using the adrenaline dodge maneuver described above, since you will need it for all subsequent boss fights . But if you can't do it, or just want to try something different when replaying this level, it's your choice. If you want to avoid head-to-head combat, there are at least a few spots around the arena where the T. rex can't reach Lara and she can shoot it from