The tossup/bonus format is the most common format used in both High School and Collegiate Quizbowl. In this format, the game consists of the reading of tossup questions which either team can buzz in on, which are followed by bonus questions that are controlled by the team that answered the tossup. If neither team answers a particular tossup, then the match goes on to the next tossup, which means that one fewer bonus question gets used.
Usually, games in the tossup-bonus format are untimed, and a set number of tossups are read with their corresponding bonuses before the game is ended and the team with more points is declared the winner. The standard used by ACF, HSAPQ, PACE, and many other question sets is the reading of twenty tossup-bonus cycles, in which case the format is sometimes called the 20/20 format. Some local high school and middle school tournaments use a different number of questions. The tossup-bonus format can also be played timed, in which case the expiration of a clock determines how many tossup-bonus cycles are read in each half of the game.
Hilariously, CBI once claimed a legal trademark on the tossup-bonus format.
Tossup questions are read to both teams; an individual must buzz in and answer the tossup correctly for their team to receive points and a bonus for their team. See article on tossups for more description.
In the tossup-bonus format, all buzzing on tossups is entirely individual; players are not allowed to confer to answer a tossup, either by speaking to or writing notes for a teammate. If neither team answers a particular tossup, the moderator states the answer and moves on to the next tossup (this is referred to as a question "going dead").
A bonus is a set of several questions that the whole team can work together to answer. Bonuses are given as a reward to the team that answered the tossup question immediately beforehand. A bonus is typically worth 30 points, and they have been standardized as three-part questions that are worth 10 points each. The moderator reads the intro and first part and gives the controlling team a chance to answer, then reads the second part and gives the controlling team a chance to answer, and then reads the third part and gives the controlling team a chance to answer. The team is immediately told whether or not each part is correct, and the correct answer is given if the team's answer is incorrect. Three-part bonuses are intended to have an "easy part" accessible to most teams, a "middle part" that about half the teams can answer, and a "hard part" that only the top teams at a given tournament should be able to answer. However, the order in which the three difficulties are asked may not always be easy, medium, hard. (The variable value bonus, which assigns different point values to each bonus question, is an unfair bad quizbowl practice which has largely disappeared.)
Teams typically have five seconds to confer on each bonus part, and the moderator uses the first answer given by any member of the team that is directed to the moderator rather than a teammate. Teams are warned when they have one second left to give an answer.
A substantial variation on the playing of bonuses is the addition of bouncebacks, meaning that if a controlling team gets a part wrong, then their opponent gets a chance to answer that part before the moderator states the answer. The controlling team still maintains control of the bonus. Rebounding teams typically have less time to confer and are not given warnings when time is about to run out. Notably, PACE Nationals uses bouncebacks.
From ACF Fall 2012, Buffalo packet
7. A daughter of Phorcys and Ceto, this figure was killed by a man on a quest to obtain her head as a wedding gift to Polydectes. For 10 points each:
 Name this monster, a Gorgon who had snakes for hair, who was slain by Perseus.
 This creature was born, along with Chrysaor, when Perseus beheaded Medusa.
 Name either of Medusa’s two sisters, Gorgons who, unlike her, were immortal.
ANSWER: Stheno [or Euryale]
Defunct styles of bonuses
Before the easy-middle-hard bonus format became completely standardized, bonus formats could vary from bonus to bonus within a tournament. Examples of such various formats included:
- four answer, 5 for one, 10 for two, 20 for three and 30 for getting all four answers correct
- two answers, each with two clues, with teams given 15 after the first clue for each answer or 5 after the second ("15-5")
- five answers, five points per answer with an additional five for all correct
- six answers, five points each (this and the above are used mainly for list bonuses)
- two difficult answers of 15 points each
- one answer, three clues of decreasing difficulty, with teams given 30 points after the first clue, 20 after the second, 10 after the third ("30-20-10")
- three answers of increasing difficulty, with teams given 5 points for the first, 10 for the second, 15 for the third ("5-10-15")
- three answers, each with two clues of variant difficulty, with teams given 10 points for the harder clue or 5 for the easier ("10-5")
- some local high school formats used one-part bonuses or bonuses that were worth 20 points
All of these forms are now strongly discouraged, if not forbidden outright, in standard high school and collegiate play for reasons of fairness.