And by ancient i mean around 1500 years ago. since slaves came from different cultures and ethnicities you couldn't tell a slave from a free man just by appearance alone (I speculate). was there a way that someone could recognize a slave just by appearance?
also how come they didn't just run away? surely they weren't kept in shackles and chains all the time?
Also, were things different for slaves from region to region? i mean, was it different in Rome that in the Arabian peninsula for example? ie: in regards to the questions above.
First off, many slaves in the ancient world did run away and the possibility was always there. There were also numerous large-scale slave revolts, most famously the one led by Spartacus that had to be put down by a Roman army. To prevent mass escapes, Roman slave owners used either the carrot or the stick. Branding, shackling, abuse, and torture were used to keep many slaves in check, while others in more favored positions were given a stipend (Lat. peculium) and much more independence. The most-favored slaves were those belonging to the emperor, who, along with his freedmen, had a hand in administering the empire.
Harper, Slavery in the Late Roman World, AD 275-425 is excellent recent study on the subject. Here he discusses different types of incentives offered to slaves.
To give just one example of a fugitive slave from a documentary source, P.Cair.Preis. 1 (148 CE) (image) is a report of judicial proceedings from the province of Egypt concerning an enslaved woman named Eutychia, who was purchased for 1,160 drachmas (a hefty sum, enough to employ some 40 men for a month). According to the report, "after she stayed with him (the new owner) for a short time, she ran away taking with her the sale contracts and much of his belongings."
Put yourself in their shoes: you are a slave, let's say the child of two Gauls captured by Caesar. Your Latin is imperfect at best, you know very few people outside of the household and those you do know you are a slave. Where do you run to? You have no property or connections and your speech immediately marks you out. To top if off, there is a reward on your return, and the shepherd you run across may have heard of it as he sees this scraggily desperate looking figure dressed in rags.
On the other hand, instances of civil strife, such as the wars of Sextus Pompey, Spartacus and provincial rebellions, seem to have been a magnet for escaped slaves. Now they have a place to run away to, and it seems those brave or desperate enough did. What is lacking in ordinary times is a destination.
For your other question, while patterns in slave owning varied enormously, it is difficult to recover actual slave conditions. It is almost certain that the status of slaves varied regionally, but we can't really say how.
Piggyback question: In the show Spartacus they paid the slave gladiators an allowance that increased with good performance. This was portrayed as making the slaves more loyal and eager to fight in the arena.
Was the practice of paying slaves/gladiators a thing? How common was it?
If a slave was paid an allowance how would they be able to spend it? It's not like a branded slave can just waltz into town, or could they?
Not a complete answer to your question but in the Roman Empire slaves who had a history of running away were often branded on their forehead with "FUG" which stood for fugitivus (means runaway in Latin). This would make it very easy to distinguish them.
Source: Johnston, Mary. Roman Life. Chicago: Scott, Foresman and Company, 1957, p. 158–177
