You shold make several steps before you can try beta.
MetaMask is an electronic wallet that is installed as a plug-in in your browser and allows you to make payments and transfers in Ethereum. Also, MetaMask allows you to buy and sell ETH for fiat money with a credit card. Details >>>
To start using MetaMask, you need to sing in. If you do not already have a wallet in MetaMask, then you should sign up by following the instructions.
Select Ropsten testnet
Beta version of EtherDragons Arena works on Ropsten testnet. Therefore to try beta you should select this network in Metamask.
SignIn / SignUp
To use beta sign in to EtherDragons Arena. If you haven't account you should create it:fill in the fields in the Sign Up form and press OK.
To get access to beta testing you should by at least one dragon. You can do this on Presale page right now. Details >>