This is a tool for playing a role-player game (RPG). The concept is readily adaptable to pretty much any game (but would require some, possibly a lot, of coding), though this implementation has a specific set of rules that are not far from DnD.

Note that this system is entirely deterministic, i.e., there is no random number generator. Randomness is created by rolling dice as normal.

The software is a web server that runs on your PC; devices on your home network (i.e. Wifi) can connect to the PC to interact as the game progresses. Note, them that it is designed for games where all the players who are present with the GM, rather than, saying playing by video conference (though the later might be possible with VPM connections to your local network - but you are on your own with that)

The game master (GM) (also known as the DM) runs the game, through a screen that controls the action, whilst each player views their character sheet on their own tablet. Another screen can also be set up to display status of all characters and the order of play.

When a character takes an action, the player announces to the GM the intention. The GM will then ask the player to roll dice as required, and the GM will enter the result into a web page. The software calculates the outcome, and the all the appropriate displays are automatically updated.

There is also a facility for players and the GM to send messages to each other.

It includes a character creation facility too.

Look at the Wiki for more details (though the home page is almost identical to this).