As in other forums, follow the gaia ToS and read the individual rules for each contest. If there is a problem, pm myself, or one of the crew or vice captains, we'll be glad to help out 3nodding

Rules for creating a contest

Anyone can create their own contest, you just need to state the rules clearly, and what the contest requires, so everything is kept fair.
If someone on the guild crew find a competition that isn't running fairly, or misbehaviour, we will be forced to either shut down the contest thread or ban the person causing it. (Although this is in an extreme case, otherwise, we'll issue warning to the people involved.)

Most of all, just have fun =) If you have any questions, please pm me.