BlogNomic has been mentioned, but here's a gratuitous plug for Agora Nomic, which is currently suffering from lack of interest (and could use a few more players) but is arguably the oldest still-living true nomic. The game sometimes has "actual gameplay" and sometimes doesn't really, but in practice mainly revolves around the rest of the rules - over 100 of them - including things like multiple privilege levels for rules, a court to decide questions and punish rulebreaking, assets that you can give someone to let them act on behalf of you, a bill of rights, offices, and, of course, proposals, all of which is written in a rather formal and pedantic style that's nevertheless the subject of much debate over interpretation. The whole thing somehow feels like maintaining a computer program written in English, and perhaps for that reason, many players are programmers; as a particular example, one valid way to play is to find bugs in the rules and try to exploit them to force through a proposal granting you a (temporary) dictatorship, which is like nothing so much as computer hacking. It's bizarrely fun.
> Agora Nomic, which is currently suffering from lack of interest
And deservedly so. I started playing once, and got chosen to be a judge. After a couple of hours reading the rules I passed judgement, and promptly got shot down/counter judged. Apparently I was technically correct, but there were a whole swag of "customary rules" which weren't written down anywhere.
If you're not going to play by the rules as written, what's the point?
Not sure when this was, and I guess this may be very belated, but I'm sorry you had that experience. Nowadays at least, although the text of the rules is interpreted much more literally than any real law system, and the policy is always to follow it where it is clear, vagueness in the rules is often interpreted in a convenient way, and there is quite a lot of (often ignored) precedent to deal with it, so it takes time to understand them. On the other hand, the CFJ system doesn't always get it right (in quite a few instances, later cases have struck down precedent without any particular reason that the answer should have changed - some cases are paid more careful attention than others, and sometimes emotion affects it in the case of scams), and often facts that seem completely self-evident to one person end up getting disputed (I've had this happen to me and observed it in others). I've learned through experience that it's best to avoid taking adverse judgements personally or getting ticked off about what seems to be misguided judging, especially if you're trying a scam.
http://agoranomic.org
The ruleset: http://agora.qoid.us/current_flr.html
An example call for judgement: http://cfj.qoid.us//1892