Keep Springtrap away from your office by playing audio in distant cameras to lure him away. Monitor the vents closely — he can cut through them to reach you faster. Prioritize keeping cameras and audio functional over ventilation unless you start getting phantom hallucinations.

Springtrap is a deteriorated Spring Bonnie animatronic suit that contains the remains of William Afton, the murderer responsible for the events of the previous games. He is the only real animatronic threat in FNAF 3 — the others (Phantom Freddy, Chica, Foxy) are hallucinations that disable your systems rather than directly kill you.