I'm looking for some example games for inspiration that allow from 10 to a large number of players at a time and can be completed in 10 to 30 minutes. I'm looking for something that would have extremely low bandwidth and not be dependent on chance or luck (i.e one player can't gain an unfair advantage because the computer put them in a better position).

Realized on the way home that more clarifications might have been helpful. I'm looking to develop a pay-to-play competition that would allow a large number of players to compete in a relatively short period of time. One way would be to have an mmo that can be completed in 30 minutes, another way would be if you could have 10 person games that finish in under 5 minutes and then have the winners compete against each other until a winner is decided. I'm interested in any genre that would make for a fun/interesting game that doesn't depend on luck, so all players should have the same choice/availability of activities/resources and follow the same rules. Some possible games that could possibly be modified into what I want, would be bztanks (too easy to create a bot), diplomacy (takes too long), risk, some chess like game. I was just wondering if there are other game types to the ones I have been considering.