100 players is definitely doable, and become even more common than before.
The biggest problem you get when you have 100+ players in a tournament is that you will probably have several people not show up for games (partially because the tourney takes a while to fill up). Just be prepared for that and have a back-up-plan for dealing with it.
My Age of Realms tournament already has 141 players after two days and I only sent like 20 invites. Either you are going to have to do something very popular or plan on sending tons of invites.
Sir. Ricco wrote:My Age of Realms tournament already has 141 players after two days and I only sent like 20 invites. Either you are going to have to do something very popular or plan on sending tons of invites.
I'm assuming a UEFA Champions League (with qualifying) tournament is popular.