You purchase a ticket for 1000 adena from the Coliseum Manager. Ticket sales cease at 5 minutes before the arena start time. After ticket sales have ceased, you can be teleported in. One note about the start time. You'll notice that the NPC says something like "the next round starts in 23:00". This is in your local time zone. I am in Eastern, and it told me the next round was at 23:00. Margarita was in Pacific and it told him the next round was at 20:00. So, don't be confused, don't second guess it like the siege times. It's in the time your computer is set to. (Thanks NC ^^)

Anyway, you get inside the arena and nothing is there. You wait until the time stated (on the hour) and the first "group" starts to arrive. Estimates were that around 30 monsters spawn every 10-20 seconds for 4 minutes. The first group is the easiest monsters. These monsters will stay in the arena until they are killed. After the 4 minutes are up (and note, in the screenshot, the Colosseum Manager give you minute-by-minute time information), a bunch of random drops appear. There is then a 1 minute break where you can finish off as many monsters as possible and collect drops.

Then, group 2 starts arriving. They also come every 10-20 seconds, they are harder. The old ones are still there if they lived (normally there is no way to finish them all off). After 4 minutes, better drops fall. Then a one minute pause to collect yourself (and the drops). Then, same thing for group 3 and 4. Group 4 is the hardest group and you get a 3 minute pause to try to prepare yourself. It has ended with 2 Baphomets and 2 Beleths in one case. In other case, the last monster was Demon.

At the end of the 4 minutes of group 4, all monsters and drops disappear immediately. If you are still alive, you are scored (Melantus is going to get back to us on what the score is) and ranked accordingly. I'm going to assume that the top 10 is top 10 of all time (not cumulative), so if you can get your name up there, it stays there until someone beats you ;)

Currently, the monsters don't drop anything. They only give you experience. This may be a bug, as the arena is still in testing. We'll see. I think this will be very fun - both to participate and to watch.

The next one is set to 11PM Eastern today. If you want to get a look at this, make yourself a test server account, scrounge up 100 adena (don't beg - just pick up stuff off the floor and sell it, most people on test can't be bothered to sell a pair of low boots to the store, so they drop it) and go to the arena and buy yourself a viewing ticket from the Assistant Manager of the Colosseum (to the left of the Manager/Ticket Booth) and check it out - 11PM ET today. (That's 10PM on the top clock on the left)

Credit for the screenshot goes to Ruben - thanks!