Urban golf is the funner, cheaper, and easier game based on traditional golf. Basically, you and your friends meet at a park, each with a single golf club and a tennis ball, then pick targets and see who can hit the ball to the target in the fewest number of "whacks" (or "strokes" if you want to get golfy).
One golf club - you can use any club you like, but you only get that one.
Tennis ball (maybe bring a spare).
Open(-ish) place to play, ideally with a limited number of other people (aka non-combatants).
Well, urban golf isn't real big on rules. If you really like lots of rules, you might want the other kind of golf. As a matter of etiquete (and a bit of safety), generally whoever is furthest from the hole is the next to hit again. You can kinda decide on rules/guidelines as you go. Things like:
What constitutes "the hole" - do we have to hit the target? Go over it? Get within a club-length of it?
Are there any mandatory obstacles - like going around a certain tree, or hitting part of the playground?
Again, urban golf is mostly about fun, so I don't get too caught up in score. The general idea is that everybody counts how many times they had to hit the ball before getting to the hole. Whoever has the fewest, wins. In normal golf, the scores are added up across many holes of play. In urban golf, I like doing just one hole at a time - it keeps everyone interested and is more fun. Usually, we don't track the score at all - just hit the ball, laugh, and repeat.