There are two versions, or "codes" as they say - Rugby League and Rugby Union. I've never understood the differtence. Mind, I never really understood the rules when I had to play Rugby Union at school many years ago. Both are pretty lethal anyway, and played without those curious RoboCop costumes that "footballers" in America appear to favour.

Best version of football to watch is Aussie Rules, even better than its close relative, Gaelic Football.