A 'ladder' is a simple list of players, which will generally be in ability order, the best at the top.

However, unlike a box league or round robin, where each player in a box plays each of the other players, a ladder only allows challenges to another player, and if they win, then the two players swap position.

The main rule is that a player can only challenge a player above them, and only if the difference does not exceed a pre-set limit.

There are three basic administrative functions:

• Create the basic ladder along with it's rules.
• Populate the ladder with the initial players.
• Add and remove players as required.

Once a player has logged in, they have two main functions:

• Make a challenge to another player.
• Add results.