Basically, I am super rusty and in an attempt to wipe off the several centuries worth of rust that my DM skill has I am developing a quick fun game.

However, when attempting to develop the game I've come across a dilemma. How to a create a space-efficient, neat, system which does the following.

1) Introduces the Players with a Welcome message
2) Asks the player whether they'd want to play or observe
3) Makes sure that only two players get in to the "arena"(red and blue) and that everyone else is denied.

The most challenging part is making it efficient and not a bunch of useless conditional statements. Another thing I'm worried about is how to separate the observers from the players(score wise).

-I would appreciate very much if someone could show me an efficient system which does that which I ask of... THANKS!