Gamechecker is a web page that allows human users to play games using rules and styling of their own. In the current version, there is no clock, i.e. you can take as long to play as you like.

Gamechecker can be found here.

The Rule Sheet box allows you enter game rules. The rules must be written in standard GDL. You can navigate through the rules using the scroll bar on the text area.

The Style Sheet must be written in javascript. The style sheet must be written in Javascript. The code must define a javascript function called renderstate that takes a state as argument and produces a DOM fragment as result. (If you do not specify a style sheet, the system reverts to standard display for states.)

Once it begins, the current state of the match is shown in the Game State area.

Once you have supplied a rule sheet and a style sheet, press the Initialize button to begin play. The Move selector will contain the legal moves in the current state. Selecting one of these moves will execute that move, and the state will be updated accordingly.

Note that you can modify the rules and the style sheet at any time, though you may need to press the Initialize button again to see the results.