We are currently rolling out updates to allow 1.7.6 and 1.7.7 clients to connect to the server.
(1.6.2 to 1.7.7 will be able to connect!)
However, Mojang's sessions servers are so unstable today that we are having trouble to know if our patch is stable enough, so in the next few hours you might be able to connect with 1.7.6 and 1.7.7 for short period of times, until we know for sure that it's stable we won't go 100%.
edit: 1.6.2 to 1.7.7 can now log on the server!
edit#2: apparently it's being blocked, working on a fix
edit#3: people can now connect once again with 1.7.6 and 1.7.7
edit#4: 1.7.8 broke things again... working on it...
edit#5: 1.7.8 now works but severely broken, please use 1.7.5
We are going to open up the BETA of Arena Brawl to everyone this weekend!
The game took longer than expected to complete because it is quite a complex game due to several mechanics like the rating, match making, multiple games per world system, custom health system, skill system and much more.