The COre COliseum (CoCo) is the place to be if you want to engage in tactics-oriented arena-style combat. We currently are offering 4e characters and combats and 3.5e characters and combats, we are happy to recommend every one to come and join us and have a good time watching pitted battles. The CoCo is a place to optimize, experiment, test and kill each other's builds and creations.
The 4th Edition CoCo (Sagaris) is currently running teams of 2 against other teams of 2 and teams of 2 against monster teams. We plan on adding more features as we can balance the rules for them. You can find the full rules for Sagaris in the CoCo's Wiki, but newer players should head to the Quickstart Guide first.
The 3rd Edition CoCo (Gladius) allows players to test their builds in a wide variety of circumstances and versus a wide variety of opponents. We feature single character versus single character fights, multi-character fights (2 vs 2, 1 vs 2) and even free-for-alls. We also have rules in place for quests and campaigns for people interested in a more structured role-playing environment. You can find the full rules for Gladius in the CoCo's Wiki, but newer players should head to the Quickstart Guide first.
The environment of the CoCo is constantly being worked on to be improved. We welcome constructive suggestions in the Tavern (in our forums) and via PM.