I hear a lot of conflicting things about this. Some say that death was super common in the arena in Gladiator fights, but others say that Gladiators had long careers and that killing was uncommon.
Which is true? Are people confusing the prisoner executions in the colosseums with professional Gladiators? Were there professional Gladiators?
While you're waiting, you might be interested in these previous threads:
Gladiatorial fights in Ancient Rome; were fights to the death as common as Hollywood leads us to believe? by /u/Celebreth
Were there any incidents where free men chose to become gladiators during the Late Roman Republic? by /u/XenophonTheAthenian