**Hnefatafl**, also known as just **Tafl**, is a family of asymmetric ancient Northern European games. The attackers start around the edges of the board while the defenders start near the centre. The goal of the attackers is to capture the king, while the defenders try to protect the King until it escapes to some designated squares on the board. ===== Brief history ===== There has been scant documentation regarding the game, and over time, the precise rules have become obscured. The sole surviving record is a narrative of the game provided by Linnaeus for the Sámi 9x9 Tablut variant in 1732; however, historians encountered significant challenges in its interpretation for an extended period of time. Many attempts at reconstruction have been made, but it was challenging to come up with a ruleset that was balanced for both sides. This provoked creative interpretations like changing the escape condition, modifying the number of steps the pieces move, changing how the king can be captured, whether the king can participate in captures, etc. The diary [[https://archive.org/details/ungdomsskrifter02linne/page/n155/mode/2up|was digitised in 2011]], and it allowed some of the dedicated fans to attempt another reconstruction, and in 2013, a balanced set of rules were found by the [[http://aagenielsen.dk/hnefatafl_online.php|aagenielsen.dk]] site. The community there continues to innovate and play test new and old variants until today. In Abstract Play, the historical Linnaean variant is used as the default variant, but some of the other popular and balanced variants from aagenielsen.dk have also been implemented. === References === * http://aagenielsen.dk/tablut_summary.php * http://tafl.cyningstan.com/page/170/tablut ===== Terminology and conventions ===== We call this set of games **Hnefatafl** games. The **defenders** is an army of **men** with a special piece called a **king**. The defenders try to guide the king so that it is able to safely escape the board. They are usually represented with white pieces (in Abstract play, it is the blue pieces by default). The **attackers** is an army of men try to capture the king before it escapes. The attackers usually have twice the number of men compared to the defenders. They are usually represented with black pieces (in Abstract Play, it is the red pieces by default). There has never been any documentation on which side starts, but modern convention was that the attackers start. However, in a lot of recent variants, it is found that the setup is more balanced if the defenders start. Variants where the defenders start are suffixed with ''-w'' in the variant name. Pieces usually move orthogonally in any direction as long as it is not **blocked**. Some variants place restrictions on the number of squares that each piece can move. The objective for the defenders is to guide the king so that it is able to escape to some designated squares. There are two main variants, **edge escape**, where defenders win if the king escapes on any square on the edge, and **corner escape**, where the king escapes on one of the four corner squares. **Captures** of regular pieces can be made via **custodian capture**, which can be aptly described using the [[http://tafl.cyningstan.com/post/1109/the-hammer-and-the-anvil|hammer and anvil]] analogy. When an opponent piece is next to one of your pieces, you may move another piece to sandwich that opponent piece to **hammer** it onto the **anvil** piece, thus removing the opponent piece. It is possible to move a piece between two opponent's pieces without getting captured. If the king is able to be captured via custodian captures, then he is known as a **weak king**. In some variants, the king is only captured via **enclosure capture**, where the king has to be surrounded on all four orthogonal sides. A king that is captured via enclosure capture is known as a **strong king**. If the king is able to participate in custodian captures, then he is called an **armed king**. Otherwise, he is an **unarmed king**. In some variants, the king may only function as a hammer or an anvil. In some variants, the centre square is marked and it has special properties. The king usually starts on this square, and it is known as a **throne**. If the king vacates the throne, then the square is called an **empty throne**. If the empty throne is able to function as an anvil, then it is known as a **hostile throne**. If the empty throne is only accessible to the king, then it is a **restricted** to just the King. Some variants **forbid** all pieces from accessing the throne, so the king is not allowed to **re-enter** the throne once it leaves. Most variants allow men to jump over the empty throne, and we say that the throne is **passable** to men, otherwise it is **blocked**. In most corner-escape variants, the corner squares are marked and they have special properties. If it is able to function as an anvil, then the board has **hostile corners**. The corners, if present, are usually also **restricted** to the king. For corner-escape variants, if pieces can be captured against the edge, then it is known as a **hostile edge**. Edges are not usually hostile, but some variants make the edges hostile to the king only. If all of the defenders pieces are surrounded by the attackers such that no piece is able to escape, then the defenders are said to be **encircled**. Encirclement is a win for the attacker in modern implementations. In Abstract Play, the win condition is triggered at the end of the defender's turn, so they get a chance to break the encirclement if they are able to. If the same board position is repeated a third time for the same player, then it is called a **perpetual repetition**. In modern implementations, perpetual repetitions are a loss for the defender. This rule used to be phrased such that it's a loss for the //aggressor//, but it was [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=1&t=112&start=10#p1610|later changed in 2021]] so that it is a loss only for the defender because in practice, this rule is only triggered by the defender, and it makes thematic sense that the attackers win if the defenders cannot win any more. In some older variants like Fetlar, perpetual repetition is a draw. **Stalemate** is a loss, so if a player is unable to move, it is a loss for that player. A **check** will be called if on the next turn, the opponent has a chance to make a move that will end the game, or more precisely when * the defenders being able to move the king to the edge or corner to win on the next turn * the attackers being to capture the king on the next turn * an encirclement has been created such that the attacker pieces have surrounded all the defender pieces. If the defender does not break the encirclement on the next turn, the attackers win * an exit fort has been created (see the [[hnefatafl#copenhagen|Copenhagen variant]] for more details). If the attacker does not break the exit fort on the next turn, the defenders win. Players may **agree to draw** if it is not possible to end the game. ===== Variants ===== It is said that there are [[http://tafl.cyningstan.com/post/1276/four-schools-of-hnefatafl|four main schools of Hnefatafl]]: - Weak armed king with edge escape (historical variants) - Strong armed king with corner escape (The Viking Game variants) - Strong unarmed king with edge escape (Imperial Contest variants) - Limited-step pieces, where the king is only allowed make single steps (Papillon's Escape variants) The first three are common, but the last one has become less popular. A lot of these variants have been tried in the aagenielsen.dk site, and below is a short write up of some of the interesting ones that are implemented on Abstract Play. ==== Linnaean ==== This is the historical variant that is based on the latest interpretation of the writings of Linnaeus. In the **Linnaean** variant, it is an edge escape with an armed king that is strong near the throne (on the throne, or on one of the four adjacent squares), but weak everywhere else. The empty throne is hostile to both the attackers and the defenders, and it is restricted to just the king. The question of whether the throne is re-enterable by the king has been a subject of contention due to Linnaeus writing that nobody can enter, but it is [[http://www.tsalo.fi/Tablut.html|argued that]] > The latter is based on the rule that nobody can enter the fort. However, it may be too strict an interpretation that even the king cannot enter. After all, what is a fort if not a place of refuge? And finally, Linnaeus' rule 10 > If the king is surrounded by enemy pieces on three sides, and one the defender's own piece on the other, the enemy may capture that piece against the king on the throne via a custodian capture. is contentious because > Rule 10 (“the soldier thus enclosed between his king and the enemy is killed”) says that if the King is surrounded from three sides, the fort can be used by the surrounding side to block. This is translated the same way in all translations. I do not really understand the purpose of this rule. If these are the only pieces still on the board, it's not sensible to take the soldier, because the King would move into its place and have two ways out. The game works without this rule. The standard implementation of the Linnaean variant allows the king to re-enter the throne and omits rule 10. [[http://aagenielsen.dk/historical_hnefatafl_rules.php|Full Linnaean rules]] ==== Fetlar ==== The **Fetlar** variant set up by the Fetlar Hnefatafl Panel in 2007 based on The Viking Game variant in an attempt to create a balanced game. It features a strong armed king with a corner escape objective. The throne and the corners are hostile. Perpetual repetition is a draw. While the game is quite balanced, there was a tendency for attackers to seal off the exits, and when the defenders have no hope of winning, they start creating "draw forts", where the defender tries to form a barrier around the king to force a draw by repetition. The attackers have to try to prevent this, and [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=1&t=24#p78|it risks exposing a corner doing so]]. [[http://aagenielsen.dk/fetlar_rules_en.php|Full Fetlar rules]] The Fetlar variant is stated here for its historical significance, but it is not implemented in Abstract Play. ==== Copenhagen ==== In the interest of making the game more interesting, in 2012, the aagenielsen.dk community came up with some [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=1&t=2&start=60#p44|modifications to the Fetlar rules]]. This resulted the **Copenhagen** rules for which there are three amendments: - there is an alternative winning condition for the defenders where they can construct something called an **exit fort** against an edge. This requires the king to be on an edge with at least one space to move, and is barricaded by its own men such that the fort cannot be broken. This reduces the effectiveness of the attackers in sealing the corners in order to produce a more dynamic game. In Abstract play, the win condition is triggered at the end of the attacker's turn, so they have a chance to break the fort if they are able to. - there is a means to capture pieces on the edges with what is known as a **shieldwall capture**, where multiple men can be captured against the edges via a bracketing move. This makes it harder to keep pieces indefinitely alive at the edges. - repetition is a loss instead of a draw. [[http://aagenielsen.dk/copenhagen_rules.php|Full Copenhagen rules]] This variant has been used in the World Tafl Federation since 2013 and has remained one of the most popular competitive variants. While this variant is balanced at high level play, beginners tend to find it much harder to play as the attackers. ==== Berserk ==== The **Berserk** variant is [[http://aagenielsen.dk/berserk_comments.php|another attempt at balancing the game based on some artifacts with differentiated pieces]] proposed by Aage Nielsen in 2011. It builds on the Fetlar variant, and it * introduces two new piece types: - the attackers have four **commanders** that can jump over normal enemy men, and can capture the king via custodian capture by using a corner or another commander piece as an anvil (but not against the throne) - the defenders have one **knight** that is allowed to **jump capture**, where it jumps over normal enemy men and removes them in the process * allows the king is able to jump over enemy men but only to and from restricted squares (throne and corners) * allows for **berserk captures**, where after any capture by any piece, if it is able to perform another capture via a single move, it is able to continue making capture moves * allows the king to make a **berserk escape**, where if it is able to reach to the corner square after a capture, it is able to immediately escape to that square and win the game * removes the encirclement win for the attackers. [[http://aagenielsen.dk/berserk_rules.php|Full Berserk rules]] ==== Total ==== There was a suggestion by Draganov in 2023 to [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=1&t=150|combine Fetlar and Copenhagen rules]]. The main argument is that repetition being a loss for the defender causes the attacker to become a lot more passive because they have no reason to attack the king, and would instead focus on sealing off the corners and the edges. With Fetlar rules where repetition is a draw, the attackers are incentivised to break up draw forts to prevent draws, which makes the gameplay a lot more dynamic. Draw forts are not easy to create, and statistically, the draw rate for the old Fetlar variant was allegedly only 7%. In the small forum in aagenielsen.dk, it was suggested that they should experiment with Berserk captures and Berserk escapes as well, and the **Total** variant that combines Fetlar, Copenhagen and Berserk rules was born. Its features are * strong armed king with corner escape goal * shieldwall captures are allowed * defenders can create exit forts * attackers can win by encirclement * pieces can make berserk captures * the king can make a berserk escape * repetition is a draw Note that unlike the Berserk variant, there are no special pieces and the king may not jump to and from restricted squares. In their test tournament, a lot of the defenders' wins were from kings jumping to the corners, so removing this ability made the games a lot more balanced. ==== Tyr ==== The **Tyr** variant is a [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=4&t=118|recent attempt to bring Berserk rules to the edge escape variant]] from 2020 by Luk Martens (Masterluke). It has gone through multiple iterations and it was tested with a lot of special pieces. In 2022, it was decided that the standard Tyr is a throneless berserk variant without any special pieces, but there is berserk capture, and the king may make a berserk escape to the edge. As with Berserk, there is no encirclement win for the attackers. [[http://aagenielsen.dk/tyr_rules.pdf|Full Tyr rules]] (note that the standard Tyr is known as "Simple Tyr" in the current rule sheet). ==== Sea battle ==== The **Sea battle** is based on the Imperial Conquest variant [[http://aagenielsen.dk/seabattle_summary.php|that was proposed and formalised in 2011]]. It features a throneless board and has a strong unarmed king with edge escape. Although it was based on a mistranslation, it turned out to be a very balanced and playable Hnefatafl variant. In the aagenielsen.dk site, the king has been themed as an unarmed capital ship, and the variant is thus known as Sea battle Tafl. [[http://aagenielsen.dk/seabattle_rules.php|Full Sea battle rules]] ==== Magpie ==== The **Magpie** variant is one balanced example of the fourth school of Hnefatafl that is played on the 7x7 board. It was a game in a book The Leprechaun Companion by Nigel Suckling. It is a corner escape with a strong but slow armed king that can only move a single space at a time. The empty throne and corners are hostile to all pieces, and the edge of the board is hostile to the king. The defenders are themed as a leprechaun carrying a bag of gold with his four friends, and the attackers are thieves trying to steal the gold. It was found that [[http://aagenielsen.dk/hnefataflforum/phpBB3/viewtopic.php?f=1&t=36&p=611#p611|the cross setup is balanced for Magpie]]. [[http://tafl.cyningstan.com/download/968/magpie-leaflet|Full Magpie rules]] ===== Boards ===== Some of the board types that are implemented on Abstract Play are documented here. We use small letters to represent the attacker's pieces and capital letters to represent the defender's pieces. * K: king * T: men (taflmen) * C: commander * K: knight ==== Size 7x7 ==== === cross === This is the standard setup for the Irish Brandubh. ___t___ ___t___ ___T___ ttTKTtt ___T___ ___t___ ___t___ ==== Size 9x9 ==== === tcross === This is the standard Sámi Tablut setup. ___ttt___ ____t____ ____T____ t___T___t ttTTKTTtt t___T___t ____T____ ____t____ ___ttt___ === starsquare === This is known as the 2526 setup on aagenielsen.dk. They have managed to generate all candidate 9x9 boards and they are viewable [[http://aagenielsen.dk/setups9x9.html|here]]. ____t____ _t__t__t_ __t___t__ ___TTT___ tt_TKT_tt ___TTT___ __t___t__ _t__t__t_ ____t____ ==== Size 11x11 ==== === tdiamond === This is the most common setup in a lot of the modern commercial re-implementations Hnefatafl. The popular Copenhagen variant uses this setup as the main setup. ___ttttt___ _____t_____ ___________ t____T____t t___TTT___t tt_TTKTT_tt t___TTT___t t____T____t ___________ _____t_____ ___ttttt___ === belldiamond === This is the standard setup for the Welsh Tawlbwrdd as proposed by R. C. Bell. ____ttt____ ____t_t____ _____t_____ _____T_____ tt__TTT__tt t_tTTKTTt_t tt__TTT__tt _____T_____ _____t_____ ____t_t____ ____ttt____ === tcross === A popular setup for very dynamic games. ___ttttt___ _____t_____ _____T_____ t____T____t t____T____t ttTTTKTTTtt t____T____t t____T____t _____T_____ _____t_____ ___ttttt___ === lewiscross === A setup [[http://tafl.cyningstan.com/page/172/tawlbwrdd|proposed by F. R. Lewis]]. ____ttt____ ____ttt____ _____T_____ _____T_____ tt___T___tt ttTTTKTTTtt tt___T___tt _____T_____ _____T_____ ____ttt____ ____ttt____ === tdiamondberserk === A modified Hnefatafl setup with knights and commanders for the Berserk variant. ___ttttt___ _____c_____ ___________ t____T____t t___NTT___t tc_TTKTT_ct t___TTT___t t____T____t ___________ _____c_____ ___ttttt___ === tyr === The standard setup for the 11x11 Tyr variant. t__t___t__t ___________ __t__t__t__ t__t_T_t__t ____TTT____ __tTTKTTt__ ____TTT____ t__t_T_t__t __t__t__t__ ___________ t__t___t__t ==== Size 15x15 ==== === tyr === The standard setup for the 15x15 Tyr variant. t__t___t___t__t _______________ __t__t___t__t__ t__t__t_t__t__t ____T__T__T____ __t___T_T___t__ ___t_T_T_T_t___ t___T_TKT_T___t ___t_T_T_T_t___ __t___T_T___t__ ____T__T__T____ t__t__t_t__t__t __t__t___t__t__ _______________ t__t___t___t__t ===== Implementation ===== On Abstract Play, the variant names are in the format {ruleset}-{board size}-{initial layout}-{optional: starting player}. For example, 'linnaean-9x9-tcross-w' is the historical rules on a 9x9 board with tcross setup, and the starting player is the defenders. If starting player is not mentioned, then attackers start. We currently have the following variants implemented: * linnaean-9x9-tcross-w (default) * linnaean-11x11-belldiamond-w * linnaean-11x11-lewiscross-w * copenhagen-11x11-tdiamond * berserk-11x11-tdiamondberserk * total-11x11-tdiamond * tyr-11x11-tyr * tyr-15x15-tyr * seabattle-9x9-starsquare-w * seabattle-11x11-tcross-w * magpie-7x7-cross ==== Visuals ==== The king piece has a different symbol depending on the ruleset: * ''~'' armed king that is strong near the throne, but weak everywhere else * ''+'' strong armed king * ''-'' weak armed king * ''♧️'' single step strong armed king * ''♢'' strong unarmed king The board is tinted orange if Berserk rules apply. ==== Notation ==== Notation used on Abstract Play is a combination of [[https://github.com/jslater89/OpenTafl/blob/master/opentafl-notation-spec.txt|OpenTafl]] and aagenielsen.dk. Squares are identified by coordinates where small letters denote the columns, and numbers denote the rows. If a regular piece moves from the square a5 to the square a7, it is denoted ''a5-a7''. If it's any other piece, then it will be prefixed with the capital letter that represents the piece (K - king, C - commander, N - knight). For example, if the king moves from the square e5 to the square e2, it is denoted ''Ke5-e2''. If a capture is made, all squares and pieces that contain pieces will be written in the capture. If the capture contains a piece other than a regular piece, the square is prefixed by the capital letter that represents the piece. For example, if a piece moves from the square f7 to the square f8 to capture three pieces, it might be denoted as ''f7-f8xe8xKf9xg8'', where the king is captured on the f9 square. Note that the captures are sorted in ascending order of columns, then rows (a5 < b4 < b7 < c3). There is no sort priority given to captures from custodian captures, jump captures, or shield wall captures. If the movement is a special jump move, then we use the caret (^) instead of the dash (-) to denote movement. For example, if a knight at e7 jump captures a piece at d7 to the square c7, it would be written as ''Ne7^c7xd7''. If there is a follow up berserk capture or berserk run, subsequent moves are written as usual, but separated by a space. For example, if a king jumps over an enemy piece on f5 from the throne at f6 to the f4 square, capturing it against the empty throne together with another piece on g4, then makes a berserk capture of a commander on a5 by moving to a4, then escapes to the corner at a1, it would be denoted ''Kf6^f4xf5xg4 Kf4-a4xCa5 Ka4-a1''. The players are warned when they are in check, but it is not recorded in the notation. ===== External links ===== * [[http://aagenielsen.dk/hnefatafl_online.php|aagenielsen.dk]]: Hosts the annual World Tafl Federation tournaments. It has a passionate community that is always experimenting with new variants. * [[http://tafl.cyningstan.com|Cyningstan Tafl blog]]: A blog with a lot of Tafl-related essays by Damian Walker. * [[https://en.wikipedia.org/wiki/Tafl_games|Wikipedia: Tafl games]] * [[https://boardgamegeek.com/boardgame/2932/hnefatafl|BoardGameGeek: Hnefatafl]]