Gladiators were either slaves sold to Gladiator schools and trained, condemned criminals, or, very rarely, paid volunteers. Sometimes, even emperors were gladiators, willingly.
They were taken as prisoners from war or were strong slaves and forced to fight to their bloody death or until they won so much that they could buy or win there freedom.
Most gladiators were slaves whose masters forced them to become gladiators to show off how much wealth and power the masters had. In some cases gladiators were volunteers who took the gladiatoral...