Overtime
Overtime is a period of a quizbowl game played if the teams are tied after regulation play has concluded and the tournament does not permit ties to stand (as most don't).
In NAQT rules, overtime consists of three tossups without bonuses. If the score is still tied after that, "sudden-death" play occurs, that is, tossups are read until a correct answer is given (in which case the team whose player gave the correct answer wins) or an interrupt penalty is issued (in which case the teams whose player interrupted incorrectly loses).
In ACF rules, overtime is solely the sudden-death procedure described above.
In PACE rules, overtime is solely sudden death, although PACE has no interrupt penalties, so the game ends (only) upon the first correct answer being given to a tossup.
Some formats that use bouncebacks (though not PACE) use complete tossup-bonus cycles in overtime, with play concluding when a team is winning after a full cycle. It is therefore possible for a team to answer an overtime tossup correctly but still lose the game.