Unlike most abstract strategy games, Tafl is asymmetrical. The king player has only one goal: get the king piece to one of the corner goal spaces. The defenders, on the other hand, are trying to prevent this and capture the king. Unlike checkers or chess, a Tafl capture takes place when a piece moves next to an opposing piece when there is a friendly piece on the opposite side. This is known as custodial capture. You can safely move your piece between two opposing pieces, but that can sometimes put you into a precarious position a few moves down the road.
All pieces in Tafl move like a rook in chess. That is, as far as they want in an orthogonal direction until they hit the edge of the board or another piece. Also, no piece but the king may occupy the throne, the center space. This is how Tafl app enforces the rules. The app's creators know that not everyone will agree with this. As it says in the app:
This is totally acceptable, mostly because it makes the app work well. If anyone has a better way to play, you can write your own app or just play Hnefatafl in Everygame the way you want.There is some controversy about the correct rules for Tafl. Our interpretation is based on a contemporary account of Tablut by Carolus Linnaeus, which is unfortunately incomplete. For this iPad version, we have chosen a set of rules which promote interesting gameplay. Please note that we don't hold these rules to be historically definitive, but we do believe they deliver a very playable version of Tafl games.
Tafl brings something fresh – ancient asymmetrical abstract strategy – to the app store in a pretty wrapper. Playing the game is easy; you just touch the piece you want to move and drop it where you want to move it to. A big white circle appears under your finger when you are touching a space where the pawn can go. This is unnecessary, but a nice touch. Each board also includes a little bit of history about that particular set-up, which is another nice bonus.
Our two main problems with Tafl should be easy to fix. For one thing, hitting the retire button – which exits the game – is far too easy. It sits at the bottom of the board and there's not "are you sure?" dialog available. The other irksome issue is that the app doesn't save your game if you exit the app. We'd really appreciate this feature. Also, and we feel bad for saying this about yet another app: let us play our own music while playing. Tafl will let your music play while selecting a board, but once the game starts, it fades out. Lame.
Since the coders at MachineCodex Software have created their own rules (from the historical record), we recommend two more be added to the app. First, if the defender moves pieces to four (or maybe only three or even two?) corners at the same time, he automatically loses. Second, it should also be forbidden to simply make the same two moves over and over. This sort of stalemating might have been good enough for the Vikings (we'll never know for sure), but we don't need it today.
We did discover one strange bug while testing the app. After basically playing the AI into a corner (it had no moves left that could prevent my winning) it made me take its turn. After waiting a while wondering what was going on, I did so and then won the game. There was no warning or anything, just what appeared to be a frozen game until I touched an opposing piece and moved it. This situation only happened once, but it's something to be aware of.
If you want to try it out, there is a free version of the app with one board – Brandubh – available. Like what you see? Grab all seven boards (Brandubh plus Fidchell, Ard Ri, Tablut, Tawlbwrdd, Hnefatafl and Alea Evangelii – see what's what in our gallery) in the paid app for US$3.99. No matter which version you get, the Tafl AI isn't the most brilliant player, and so we recommend face-to-face gaming whenever possible. Mugs of ale are optional.