Short-term Tactics for Both Sides
So far, very little mention has been made about capturing the pieces. As with many games of strategy, simple material gain is not the aim, and concentrating on capturing pieces often leads to bad strategy. But in tactics capture, or the threat of capture, plays a bigger part.
Some of these tactics are borrowed from other games that have been more rigorously studied, chess in particular. In these cases I have adapted chess terminology where no other exists.
This is a situation in which the opponent can be induced into making one predictable move, and often forms a part of strategy later in the game. One form of this is to threaten the king with immediate capture, or to threaten immediate escape with the king. In either case the opponent is forced to react to the threat or to immediately lose the game.
Another form is more often available to the attacker, and that is to restrict the movement of the opponent to such an extent that only one move is available.
A less potent form of this tactic is to threaten immediate capture rather than immediate victory. While the consequence of ignoring the threat is not so catastrophic, it might still be enough to induce the opponent to react to the threat at the expense of whatever other plans they had.
Just as in chess, the fork exists as a tactic in hnefatafl. One piece can simultaneously threaten two others with capture; if the threatened player moves to protect one vulnerable piece, the other is immediately captured. As all pieces except the king are of equal value, the threatened player must choose which to protect based on its current strategic position, and a secondary aim of the fork is to induce the opponent into making a predictable move to which the response has already been calculated.
As pieces do not capture alone, there are two forms to the fork. In the first, a piece is moved between two enemies, each of which is then threatened with capture by other pieces on the board. In the second, less common situation, two pieces are adjacent to two opponents, when a third piece is moved into a position from which it could capture either opponent.
This is where a piece is held in its place by the threat of dire consequences if it moves. Despite the uniformity of pieces there are more broad categories of pin in hnefatafl than in chess. The most chess-like situation is where a piece is pinned to the king. The king would be threatened with capture except that a single defender is blocking the final capture.
Another form is against the edge; a single attacker lies between the king and his objective. If the attacker moves out of the way, the king will escape immediately and win the game.
The third type if pin is when two pieces offer each other mutual protection. If one moves out of position the other will be captured immediately, a position potentially holding one or both threatened pieces in place.
Four pieces in a close square is an invincible formation. Called a "tower", this formation prevents any one piece from being individually surrounded. This tactic is not shared with chess, but is common with games that capture pieces by surrounding as in hnefatafl. When the king's side uses this tactic, the king can be one of the four pieces, or instead four defenders can be used.
It is essentially a static formation; once one of the pieces moves, the tower falls apart and the pieces become vulnerable once again. So the defender might use it as a temporary measure to protect the king from a real threat of attack, intending to break it up when the threat has been headed off. The attackers, if using it in a blockade, would place it in a part of the blockade opposite to that which they intend to advance.
Next: Play Hnefatafl Here
Forks - How frquently do people aim/setup/execute forks (knowingly and admit it) and how frequently do towers occur (I haven't witnessed one yet, nor built one), is it advisable as an opportunity cost?
Boulderman - 12:58, 29/03/2017
I've occasionally used forks and had them used against me. Most of the times I've used them, they've been an opportunity I've seized a move or so ahead, rather than something I've planned for.
I don't know how often towers are used; I think I added that section after they were discussed on another web site. I've seen them used most often by a desperate defending side protecting the king, as in the lowest example on the diagram.
Damian Walker - 17:16, 29/03/2017
Say the opponent traps all 4 corners, how do you open those corners back up?
norseman - 19:12, 19/12/2018
That's one of the down sides of corner-victory versions of Hnefatafl, norseman. If the attackers are adjacent to the corners, you can capture them by sandwiching them between your defender/king and the corner square. This is because in corner-victory hnefatafl games, the corner squares are counted as a piece of either colour for the purpose of capturing.
If the attackers have left a space behind their lines, and have closed off all four corners that way, then the game is lost for the defenders (see Watching the Exits on the Attack strategy page). The defender's only hope is to move out early to take control of at least one corner for themselves, and prevent a complete blockade from happening.
Damian Walker - 05:23, 21/12/2018