How many people fought in the colosseum

It depended on the size of the gladiatorial games. The size of these events varied and sometimes emperors organised massive events. Trajan was said to have celebrated his victories in Dacia with 10,000 gladiators (and 11,000 animals) over 123 days. The staging of big gladiatorial shows was enormously expensive. Augustus legislated a cap on private and public expenditure on the gladiatorial games. The maximum imposed for games organised by senior officers of state was 120 gladiators. The cost of this would have been 25,000 denarii. Bigger games could cost as much as 180,000 denarii. Marcus Aurelius also legislated a cap some 180 years later.