Just something I wrote for fun as a test project.
I don't even know the rules yet, but this game allows you to make moves by drag and drop and to change the element of your piece by left click.(I've just been saying you can move then change any piece's element after your move and one element is unable to take a piece of it's weakness element otherwise the same game as chess).
You will need Leiningen 2.0 or above installed.
To start a web server for the application, run:
lein ring server