You're in a 20m long hallway. There is an exit. You must reach the exit to win but you can only cross half of the remaining distance at a time. There's also other players trying to get to the exit and you can fight them but you can only be hurt for half of your remaining life per hit. Can you reach the end? Can anyone be killed? Is there cake beyond the exit? It's all very philosophical.
Firstly, register a new account and make a character. You can have unlimited characters on one account. You and everyone else are in a 20mx20m room. You can talk (say, shout), move (forward, backward) and FIGHT. (fight, shadowbox)
All combat is done automatically by the system. Fighting is done via Fighting Arts, Combos, and Stances. Go into your Dashboard and create Combos. You can change your Stance (stance [name]) at any time in or out of combat. Each Combo can be keyed to multiple Stances in the combo editor. Changing your Stance makes the Combos that you have keyed to them available for use immediately.
Fighting Arts can be literally anything from basic punches and kicks to elaborate acrobatic attacks, magic spells, energy beams, summoning massive ghost trains, anything. Arts can also be dodges, parries, attack redirects and blocks. Zeno's has no NPCs or Items so everything is up to the imagination.