I'll open this post by stating explicitly that no other game in existence has anywhere near as robust and intricate of a combat system. It is well balanced, with over 16 different choices of weapons each with their own unique strengths and weaknesses.
Furthermore there are several non combat skills available, from pick pocketing to locksmithing to healing, so there is usually an avenue for anyone.
RP is mandatory in game, perma death can occur, and PvP and PvE options are available. There is basically no magic and it is set in the Roman time period with the main city clearly representative of being Rome itself. There are options for characters to join the Legio (soldiers), constables (police), as well as criminal organizations, gladiator stables, and many more.
The gameworld is humongous with over 100k unique areas, dozens of different areas to fight different mobs, regular worldwide GM run events that can impact the game for decades later.
It's been out for over 20 years, and isn't shutting down any time soon. Free to play.