Someone walk me through this whole arena premise, would you? 

Me being new here, and me liking exploding giblets and crazy ass action, I'm trying to grasp this RP section. Some of the RPs keep referring to mechanics, without actually listing the details. Do arena RPs have some kind of default mechanic system that everyone knows about? Or are mechanics specific to each RP? What's with this tier system I hear speak of? 

I'm asking because this looks like fun, but I don't want to splurge my noob juices over everything. 

Cheers for any answers/pitch fork armed mobs.