What were living conditions like in ancient Rome?

At the bottom was the slave, lowly and kept in chains you might think, although this was very often not the case. Next came the freemen, these were slaves freed by manumission. They could become wealthy in their own right, but would forever carry the name of the family that freed them. Further up the social ladder was the Plebs, these were the land owning Roman citizens, this group had no limit to their upward mobility, in fact 30% of Rome's Emperors came from the Plebeian class. These are still just the little people though. Now we are getting into the upper classes with the Equestrian order, or the Roman Knight. Finally we have the Patricians. These are the money men and power brokers of Rome, originating from the greatest families and commanding massive wealth.

One thing that always strikes me about Roman society is the contradiction that often accompanies its strict rules and customs. Rome was ordered strictly by class, but everybody above the slave had the opportunity to improve their standing massively. Even the slave in many, many cases was able to gain far more than freedom.