Tartarus is a persistent online war game where the player controls a clan of self-replicating "titans". Players issue orders every day (or three times a week if playing the slow game) and receive the results the next day. The tiny game client is so small it can run in a browser, or can be downloaded onto a player's machine and run from there. The whole program is about 200KB, and it is free.

Anyone who has played an old PBM or PBEM game will be familiar with the one-turn-per-day format, but it's one which has fallen from favour in recent times, as the processing power of home PC's and internet technology have both improved.

Tartarus is a descendant of these games, although it has been upgraded so that the game client can download and send turns itself, as well as importing tactical information sent from other players.

The interface is a 2D hex map showing the terrain of the "battlesphere". Line of sight is important, and unexplored areas are blank. Players can harvest the biomass growing on the map and spawn new units from their breeder titans. Each new generation can increase the technology of systems and weapons. Eventually this tech-race reaches a cap, which gives new players a chance to catch up to the elders (eventually).

Players are encouraged to be aggressive by the scoring system, but new and old clans are separated by several simple but effective rules.

Combat itself is straightforward, but large battles can take weeks to resolve themselves, while wars can last for months. Skilled clans are very rarely completely destroyed, so even a heavy defeat in battle can be recovered from.

Last of all the game is completely free, although after a while players can opt to pay a flat fee (around £3 per month) to receive in-game benefits, namely a larger clan and better tech.

All up, Tartarus is an absorbing successful game. Some players have been playing for several years. The interface however is very dated, and will not appeal to those raised on the graphics-intensive games of the last 10 - 15 years. Perhaps it would benefit from incorporating flash graphics, rather than the simple Java-based client, but the interest of the game comes from the pure strategy and tactics, not the graphics. It will appeal to the dedicated war gamer rather than the average computer gamer.