'The Games' is a diverse and ambiguous term within the Empire used for all sorts of entertainments normally bloody and violent games like gladiator fights and violent races. The best part of all of this is that the games are generally free, seeing as they keep the people distracted and content for a few hours.
Most games take the form of either beast fights or gladiatorial combat and both are popular and wide spread throughout the Empire with each world having at least one grand arena and many thousand of smaller fighting pits.
The main difference between the arena fights and pit fights would be the 'morals' or 'social status' of the establishments. Arenas generally host more 'honorable' fights and tends to attract more 'civilized' crowds while pit fights go along the lines of: anything goes. A example would be in the arena most fights are set up to be 'fair' while in the pit fights some fights are clearly one sided (Ex: rebellious unarmed slave vs a hell beast)
The Games have become a massive business with many wealthy families invested into the commerce that accompanies it (Vendors, transportation, providing of slaves and beast, trainers, and many other roles) they also require a massive amount of living capital to keep running with billions of slaves dedicated to both arena and pit fights and uncountable numbers of beasts.
Gladiators are seen as rock stars in Rin society with some gaining fame, glory, and eventually freedom. During there time as fighters they tend to live luxurious, expensive, and rather wild lives full of fancy toys, drugs, and concubines. Pit fighters on the other hand are dregs and not expected to live very long. They are kept in crude containment rooms with little food or water.
Both Pit Slaves and Gladiators can come from the same people: Runaway slaves, prisoners, war captives, and Xeno slaves. Most of such individuals are obtained by less then moral means and sold with about the same morals. Once they are bought they either go to the pits or are sent to Gladiator Schools (Run by merchant families) in these schools they are trained the basics of fighting and such and eventually sold to the highest bidder to the guilds.
The Pit slaves receive all sorts of training from nothing at all to advance martial arts to advance swordsman techniques. While it is considered immoral, unethical, and rather low to cyberneticly enhance a Gladiator there is no such stigma for Pit slaves, many are given multitude of weapons, enhancements, and fancy toys all for the bloody and violent enjoyment of the masses.
Out of this trade have rose many powerful Guilds and many rich and cruel Guild Masters who come from all walks of life (most have a slaving back ground) they are a lower noble caste in the Empire although some have risen to great fame and fortune.
Now location wise arenas and pits vary widely although on most worlds Arenas tend to be mega structures on the surface while the pits are in the under belly of the world although on some worlds this varies (It really depends on the residents of said world) on most border worlds arenas are hard to come by while the opposite can be said for the Core Worlds.
Now before you start flying around the "Waste of Money card" it really isn't. It distracts the citizens of the Empire, keeps rather violent individuals off the streets and either entertained or employed, and also allows the State to test out new bio-logical weapons, execute prisoners, and keeps billions employed (Take that trump)