Copied from their FAQ page:
What is LeetCoin?
LeetCoin is a competitive gaming platform where gamers can play against each other for bitcoin.
Is it hard to get started?
All you have to do is sign in, make a deposit, select a server, and play! If you are still looking to get your some bitcoin, connect to one of our promo servers and play for free!
Do I have to be an expert?
All skill levels are welcome. Promo and low stakes servers are available so you can practice or warm up with little to no risk.
How do I get into my first game?
Login using your steamID, Pick a promo server (like this one) and register then connect
Can I earn free bitcoin?
Log in and select one of our promo servers—they require no deposit, and there is no loss for dying. Yes, we are giving bitcoin away on these servers. Gather your friends and take advantage of it.
http://leetcoin.comIf you want to try it out risk free, just hop on their promo server for free coins too. Once you have enough, you can play on the regular servers!
Game on!