Ah, thanks for responding.
Make things up as you go along? That's what I do most of the time.
Also keeping rules partly unkown to the players prevents them from seeking loopholes and allows you to rebalance midgame.
Yeah, but I'd like to have a ruleset of some sort at least for character creation so that players have some idea of what they're capable of and I have some basis for adjudicating conflict.
As for complex rules, you don't need them to start out. I suggest making a simple, basic RPG to start out with, just to get the feel of things. As you host it, you'll find all there is to know about hosting a game.
But I don't even know how to make simple rules. That's my problem mostly. I've seen games where people just make up rules on the spot, it seems, and I don't know how to do that.
What kind of game are you wanting?
All you've said is you want it to be multiplayer. What setting do you want? What ratio of freeform and rules do you want? How complex do you want it? Give us more info and we will help.
Ah, well, I guess I don't have much in the way of setting. It's mostly based off of a theme. The players are all supposed to be a group of friends that all grew up together in the same village. Then, for some reason (which I have not yet figured out) they need to all travel together somewhere. Part of the idea behind this was that characters could have a shared background, and could freely make up details at any moment in the campaign, and any player character involved in the story could give their side of the goings-on if they disagreed with how they were portrayed. I would very much like it if the game mechanics rewarded players for telling these stories (possibly by giving them some success in any current challenge that the story relates to).
The actual setting isn't very fleshed out. I know I don't want just another generic European medieval fantasy setting. All the players would be human, and they would have heard rumors that certain people from certain other places may not be quite human, but there are no explicit elves or dwarves or goblins.
As for rules, as I said, I want something for character creation (though, if stories of past adventures somehow define characters, maybe that isn't so necessary) and rules for resolving conflict. I don't want fights to drag on; if they can end in something other than death or knockouts, that would be a bonus. I also would like a system where some player can be non-combatants and not be rendered useless.