Gladiatorial bouts were originally part of funeral ceremonies. Many ancient chroniclers described the Roman games as an import from the Etruscans, but most historians now argue that gladiator fights got their start as a blood rite staged at the funerals of wealthy nobles.

Were gladiator fights rigged?

They were semi-choreographed, like WWE fights. Gladiators would be trained for months to face off against competitors. A more heavily armoured Gladiator like a Murmillo would be trained to block and dodge attacks from their usual opponent, a Hoplomachus or Retiarius. There were many events that gladiators took part in.

Did gladiators ever fight in wars?

Yes, they did at times. During the 3rd Servile war lead by none other then Spartacus of Thrace. Yes, roman soldiers were trained to kill more proficiently but they were not trained in the art of an arena fighter. They enlisted aged gladiators that were once champions, to train the Romans against the threat.