Why must I have 'completed at least five games to enter tournaments'? 

Because we are getting too many players joining tournaments who have no understanding of how games work here on chess.com, and will join a tournament and then just leave, ruining a tournament for other players since then we get a lot of no-shows. Requiring just 5 games is not a lot. Most active people here have hundreds of games. Should only take you a couple weeks to complete 5 if you start now.

Thanks.

In the 1400-1800 official chess.com tournament, in Defacto's group, there are two players who have only completed 3 games each on chess.com. That doesn't bother me--a player with 3 games is fairly likely to know the rules--but it implies the code checking that a player meets the entrance criteria may be faulty. Just an FYI for the staff.

Thanks, but we didnt actually implement all of the various rules until several days after the launch so that's why you'll see some players like this.

Ahh, cool. :)