The costumed characters posing for pictures outside the city's most famous attraction have been hit by a legion of complaints from tourists, about the exorbitant prices they charge and the shabby state of their uniforms.
Now the 21st Century gladiators are facing a different kind of battle to that of the fighters they are trying to emulate.
The city's authorities have decided to clamp down on their industry, and from the end of this year modern-day gladiators will have to charge fixed rates and adhere to a strict dress code.
Visitors' shock
Currently, anyone dressed as a gladiator can stand outside the Colosseum and pose for a picture with tourists.
The unofficial price for a shot ranges from two to five euros, although more than twice that is not uncommon.
Suzi Berg, a British tourist who visited the city two weeks ago, told BBC News Online there was no mention of payment until after the photographs had been taken.
"They tried to charge us $40 for two photos," she said. "We were in shock the whole day."
Under the new rules, Rome's tourist-seeking gladiators will have to display their prices in a prominent place.
They will also have to pass an English proficiency test. If successful, they will be given an official centurion licence badge.
New tunics
The modern gladiators are also destined for a makeover.
They have been told to discard their plastic helmets, T-shirts and sandals and invest in metal headgear, authentic breast-plates, tunics and shin-high leather boots.
"They definitely look plastic and cheap at the moment. The less like Halloween costumes and the more authentic the better," said American tourist Sergio Buccilli.
Swords will remain plastic, however.
In March, police caught a gladiator with a real sword and he now faces up to three years in jail for carrying illegal arms.
Roberto Cohen, the self-styled head of a 40-strong gladiator troupe, said he would need to go shopping as a result of the new regulation.
"I'll need to buy a new helmet which will probably set me back 300 euros ($300), but it's just something I have to do," he said.
Mr Cohen also saw the positive side of the new regulations.
"Our role as a tourist attraction has been recognised after eight years of battles," he said.
Further onslaught
The attack against the gladiators does not even end there.
Belgian tourist Martine Bekaert said they needed an etiquette and acting coach as well as a makeover.
"It is a good idea to try to recreate history, but it should give a real natural flavour of the times," she told Reuters news agency.
"At first glance the gladiators are very nice, but then you get a bit closer and it is just a group of men hanging around smoking."
Suzi Berg added: "They're not exactly Russell Crowe, either."