The Pulsar Chess Engine plays Chess with multiple levels and six Chess variants: Chess960, Crazyhouse, Loser's Chess, Atomic, Three Checks and Giveaway(also known as Suicide Chess). The first few years of its development it only played chess, but over time I taught it the variants it knows. In its chess play it values mobility and active positions over just material(though its play is sound for whatever level is chosen in terms of standard material play) and with the variants, each has its own style. Chess960, Three Checks and Crazyhouse are the more chess like variants that use more chess skill and adoptable to learn to play for anyone with chess interest. The rules of all games are in app.

All games played that end with a result or resignation are logged. Users can open their log file in App on the game menu. If the game is a chess game, Crafty engine analysis is available.

Pulsar has levels of play from beginner too advanced and includes the rules of its games in app. Games with a time control are the hardest though Pulsar doesn't call the player's time. The time is more to handicap Pulsar's strength, but users will have a clock and can see if it's gone negative if they want to play the time control.

The game button - new game menu item, lets the user control the variant and difficulty. It defaults to Chess at Easy(lowest level) but remembers the current settings when the App restarts. There are some choices of chess pieces and board color schemes. The Pulsar Chess program was originally developed by me for computers starting in 1998 and came to mobile for the first time in 2014. The original engine work had stopped in 2009 at that time.

Pulsar's board is accessible to the blind using Voice Over, a screen reader. Tap on a square and it will say whats on it and double tap to move or choose from three move methods.

Pulsar began as a chess program and later learned variants. It ran extensively on two chess servers for many years both at chess and variants. The ratings on the board reflect strength I saw in rated play on handicapped bots. They are not 100% exact but generalizations I made from the various bots I ran at different settings.

If in the new game selector, Play vs. Computer is unchecked the user can move for both sides. This is to allow two people at same location to use the App as a board for a game and have the app enforce move legality and results for whatever variant is selected, such as a normal Chess game or a Variant.

Pulsar2009-b is used on all platforms, computer and here on iOS and if users go to the support link they can get free binaries that run on the different computer operating systems on clients that support the Winboard Protocol. We use the Winboard Protocol, not UCI, because it fully supports all our variants.

What’s New

Version 1.80

German Translation


Michael Adams
10.6 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad and iPod touch.


English, French, German, Italian, Spanish

Age Rating


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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