[KaVir]

Lasher has already confirmed that if he goes for the 4 (or 5) options, players will be able to select any combination for searches using check boxes.

Thus if you want to find games that accept money in any form at all (the equivilent of the 2-choice suggestion) you could search like this:

[X] Payment and/or donations required to play.
[X] Payment and/or donations accepted, has results in-game.
[X] Payment and/or donations accepted, no results in-game.
[ ] Neither payment nor donations accepted.

Alternatively, if you want to find a game where money has no in-game effect (but don't care about unrewarded donations or mugs and t-shirts that can be purchased from the website), you could search like this:

[ ] Payment and/or donations required to play.
[ ] Payment and/or donations accepted, has results in-game.
[X] Payment and/or donations accepted, no results in-game.
[X] Neither payment nor donations accepted.

I guess if you don't click any boxes at all, it'll be the same as if you'd clicked them all, except that it would also show muds that hadn't yet specified their payment model.