Promotion (chess)

Promotion in chess is a rule that requires a pawn that reaches the eighth to be replaced by the player's choice of a bishop, knight, rook, or queen of the same . The piece chosen cannot be another king nor another pawn. The new piece replaces the pawn on its square on the same move. The choice of the new piece is not limited to pieces previously , thus promotion can result in a player owning, for example, two or more queens despite starting the game with one. 
Pawn promotion, or the threat of it, often decides the result in an endgame. Since the queen is the most powerful piece, the vast majority of promotions are to a queen. Promotion to a queen is also called queening; promotion to any other piece is referred to as underpromotion .
If the promoted piece is not physically available, FIDE rules state that the player must stop the game clock and summon the arbiter for the correct piece. Under US Chess Federation rules and in casual play, an upside-down rook may be used to designate a queen .
Promotion to various pieces.
Promotion to a queen is the most common, since the queen is the most powerful piece. Underpromotion (promotion to a piece other than a queen) occurs more often in chess problems than in practical play. In practical play, underpromotions are rare, but not extraordinarily so (see table below). As the most powerful piece, the queen is usually the most desirable, but promotion to a different piece can be advantageous in certain situations. A promotion to knight is occasionally useful, particularly if the knight can give immediate check. A promotion to a rook is occasionally necessary to avoid a draw by immediate stalemate that would occur if the promotion was to a queen. Promotion to a bishop almost never occurs in practical play (about one game in 33,000). (See Underpromotion: Promotion to rook or bishop for examples of underpromotions to rook and bishop made in order to avoid stalemate.)
The percentage of games with promotions can be misleading because a player often resigns when they see that they cannot stop their opponent from promoting a pawn, or at least not without a significant loss of material or other serious situational disadvantage. In the 2006 ChessBase database of 3,200,000 games (many at grandmaster or master level), only about 1.5% of the games include a promotion. In these games (counting only once the games in which the same player promotes more than one pawn to the same piece) the proportions of promotions to each piece are approximately:
This suggests that about 3% of all promotions are underpromotions. The frequency of truly significant underpromotions is, however, smaller than this. A player may promote to any piece they wish, regardless of whether or not such a piece has been captured. In theory, a player could have nine queens, ten knights, ten bishops or ten rooks, though these are highly improbable scenarios. Some chess sets come with an extra queen of each color to use for promoted pawns. If an extra queen is unavailable, it is often represented by an upside-down rook instead, though this convention is not universally recognized in organized play.
The diagram shows a position from the game between Bobby Fischer and Tigran Petrosian in the 1959 Candidates Tournament in which each side has two queens. Four queens existed from move 37 until move 44 . 
Very few games have been played with six queens; two examples are Emil Szalanczy–Nguyen Thi Mai (2009) and David Antón Guijarro–Alejandro Franco Alonso (2011). In the first game each side had three queens after move 58 until move 65. The game ended in a draw with a single queen on each side. In the second game both sides also had three queens, but Black ultimately resigned, with a single queen on both sides.
Strategy.
The ability to promote is often the critical factor in endgames and thus is an important consideration in opening and middlegame strategy. Almost all promotions occur in the endgame, but promotion in the middlegame does happen.
Promotion occasionally occurs even in the opening, often after one side makes a , as in the Lasker trap, which features an underpromotion to a knight on move seven: 1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3 Bb4+ 5.Bd2 dxe3 6.Bxb4 exf2+! 7.Ke2 fxg1=N+! Schlechter–Perlis, Karlsbad 1911 could have featured a promotion to queen on move 11: 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5 5.Qb3 Qb6 6.cxd5 Qxb3 7.axb3 Bxb1? 8.dxc6! Be4?? 9.Rxa7! Rxa7 10.c7 threatening both 11.cxb8=Q and 11.c8=Q. Perlis avoided the trap with 8...Nxc6!, losing more slowly. The British grandmaster Joe Gallagher pulled off a similar idea a half-move earlier in Terentiev–Gallagher, Liechtenstein Open 1990: 1.d4 Nf6 2.Bg5 Ne4 3.Bf4 c5 4.c3 Qb6 5.Qb3 cxd4 6.Qxb6 axb6 7.Bxb8? dxc3 8.Be5?? Rxa2! and now White could have resigned, since if 9.Rxa2, ...c2 promotes the c-pawn . Another example occurs after 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Ng3 h5 6.Bg5 h4 7.Bxf6?? hxg3 8.Be5 Rxh2! 9.Rxh2 Qa5+! 10.c3 Qxe5+! 11.dxe5 gxh2, with the dual threat of 12...hxg1=Q and 12...h1=Q, as in Schuster–Carls, Bremen 1914 and –Torre, Mexico 1928 . Note that 10.Qd2 (instead of 10.c3) would have been met by 10...exf2+! 11.Kd1 (11.Kxf2 Qxd2+) Qxd2+ 12.Kxd2 fxg1=Q rather than 10...Qxe5 11.dxe5 gxh2 12.Nf3 h1=Q 13.0-0-0 with a strong attack .
There are also a few opening lines where each side gets a desperado pawn that goes on a capturing spree, resulting in each side queening a pawn in the opening. An example is seen in the position diagrammed, where play continued 10... bxc3 11. exf6 cxb2 12. fxg7 bxa1=Q 13. gxh8=Q.
Both players promoted by White's seventh move in Casper–Heckert: 1.e4 Nf6 2.Nc3 d5 3.e5 d4 4.exf6 dxc3 5.d4 cxb2 6.fxg7 bxa1=Q 7.gxh8=Q.
History of the rule.
The original idea was that a foot soldier that advanced all the way through the enemy lines was promoted to the lowest rank of officer. In the Middle Ages, the queen was much weaker than now, and its only allowed move was one square diagonally. (It was earlier called "farzin" or "ferz", from the Persian for "vizier"). When the queen and bishop got their new moves, chess was radically altered. When the "fers" became the queen, there were objections that a king should not have more than one queen .
At different times, the pawn could only promote to the piece of the file on which it promoted, or on which it started (a queen if on the king's file). In Italy in the 18th and early 19th centuries, the pawn could only be promoted to a piece that had already been captured. Likewise, Philidor did not like the possibility of having two queens, and in all editions of his book (1749 to 1790) he stated that a promotion could only be to a piece previously captured. Lambe also stated this rule in a 1765 book . If none of the promoting player's pieces had yet been captured, the pawn remained inactive until one of the player's pieces was captured, whereupon the pawn immediately assumed that role . A player could thus never have two queens, three knights, three rooks, or three bishops . One old set of chess rules said that "a promoted pawn became a ferz, with the move of the queen".
The restricted promotion rule was applied inconsistently. Jacob Sarratt's 1828 book gave unrestricted promotion. By Sarratt's time, unrestricted promotion was popular, and according to Davidson it was universal by the mid-19th century . However Howard Staunton wrote in "The Chess-Player's Handbook", originally published in 1847, that according to Carl Jaenisch the restricted promotion rule was still in force in northern Europe, Russia, Scandinavia, and Germany .
1862 British Chess Association rule.
Although the current rules of chess require a pawn that reaches the eighth rank to be promoted to a different piece, that was not always the case. Wilhelm Steinitz, the first World Champion, in his 1889 work "The Modern Chess Instructor", endorsed the then current "Code of Laws of the British Chess Association" . In that code, Law XIII said, "When a pawn has reached the eighth square, the player has the option of selecting a piece, whether such piece has previously been lost or not, whose names and powers it shall then assume, "or of deciding that it shall remain a pawn"." (emphasis added). Steinitz explained the purpose of this rule by referring to the position diagrammed at left, which he cited from Johann Löwenthal's "Book of the London Chess Congress, of 1862":
If White plays 1.bxa8=Q?? (or any other promotion), Black wins with 1...gxh3, when White cannot stop Black from checkmating him next move with 2...h2. Instead, White draws by 1.bxa8=P!, when 1...gxh3 or 1...Kxh3 stalemates White, and other moves allow 2.Bxg2, with a drawn endgame . Steinitz wrote, "We approve of the decision of the London Chess Congress, of 1862, although the 'dummy' pawn rule was denounced by some authorities." The same rule and explanation are given by George H. D. Gossip in "The Chess-Player's Manual" .
The broad language of Law XIII also appears to allow promotion to any piece "of either color". This led to the whimsical joke chess problem diagrammed at right. White is to play and checkmate in one move. No solution is possible under modern-day rules, but with Law XIII in effect the surprising solution is 1.g8=(Black N)!, when the newly promoted knight blocks its own king's flight square . Other amusing problems have been created involving promotion to a white or black king, which Law XIII also appears to allow.
Howard Staunton vigorously opposed the 1862 rule when it was proposed, but the tournament committee passed it by a large majority of votes . However, it did not catch on. Philip Sergeant wrote :
A correspondent in the May [1865] "Chess World" ... did not exaggerate when he wrote that the B.C.A. Code had been very generally rejected by British amateurs, and emphatically condemned by the leading authorities of America, Germany, and France. In particular, the absurd "dead Pawn" rule, against which Staunton had made his protest in 1862, had failed to win acceptance.
The tournament book of the London 1883 international chess tournament (originally published in 1883) contains a "Revised International Chess Code", which was "published for the consideration of Chess Players, and especially of the managers of future International Tournaments". Unlike the 1862 rule, which allowed the pawn to remain a pawn, it requires that: "A Pawn reaching the eighth square must be named as a Queen or piece ... ." 
Underpromotion.
Promotion to a knight, bishop, or rook is known as an "underpromotion". Although these pieces are less powerful than the queen, there are some situations where it is advantageous to underpromote.
Underpromotion to a knight.
Since the knight moves in a way which the queen cannot, knight underpromotions can be very useful, and are the most common type of underpromotion.
In the diagram, given by World Champion Emanuel Lasker, White has a huge disadvantage. Promotion to a queen (by 1.exd8=Q?) would still leave Black ahead in material. Instead, promotion to a knight with 1. exd8=N+! wins by virtue of a fork: 1...K(any) 2.Nxf7 followed by 3.Nxh8 leaves White a piece up with a winning endgame.
Promotion to knight may also be done for defensive reasons; a 2006 game between Gata Kamsky and Étienne Bacrot is such a case. White threatens to capture the pawn or checkmate by Rh1 if the black pawn promotes to a queen, rook, or bishop. The only move that does not lose for Black is 74... e1=N+! The resulting rook versus knight endgame is a theoretical draw (see pawnless chess endgame). In the actual game, mistakes were made in the rook versus knight endgame and White won on move 103 . This is a standard defensive technique for the endgame of a rook versus a pawn .
Tim Krabbé points out that Zurakhov–Koblencs furnishes a very rare example of a game with two "serious" underpromotions to knight. In the first diagram, Black threatens 57...Nxg7, and if White avoided this by promoting to queen, rook, or bishop, Black would reach a drawn position with 57...Ne7+! and 58...Nxg8. The "only" winning move is 57. g8=N! Krabbé notes that this is a rare example of a non-checking knight-promotion.
Twenty-one moves later, the players reached the position in the second diagram. Once again, a promotion to anything other than a knight would be a blunder allowing a knight fork, e.g. 79.c8=Q?? Nd6+ and 80...Nxc8, with a drawn ending. White instead played 79. c8=N+! (Here, there are other winning moves, such as 79.Kc5.) 79... Kb8 80. Kb6 and Black resigned, since White cannot be stopped from promoting a third pawn—this time to a queen.
This was the 71st move of a game between Vladimir Akopian and Sergey Karjakin at Nalchik, 2009. After 71.a8=Q??, 71...Qxb2+, followed by alternating checks on the a and b files, would give Black a perpetual check, so Akopian played 71. a8=N!, and Karjakin resigned, as 71...Qxb2+ would be met by the cross-check 72.Nb6+, which in turn forces 72...Qxb6+ 73.Kxb6, with an easy win for White.
An example of underpromotion to a knight occurred in the game Peter Svidler–Vladimir Malakhov, played at the FIDE World Cup in December 2009 at Khanty-Mansiysk in Siberia (Slav Defense a6):
and White resigned because of 32.Rxe1 Qf2+ 33.Kh1 Ng3# or 32.Kh2 Qxb2+ 33.Ne2 Qxe2+ 34.Rf2 Qxf2+ 35.Kh1 Ng3#. If 31...dxe1=Q??, it is White who mates with 32.Bxf7+ Rxf7 33.Qxf7+ Kh8 34.Qf8+ Kh7 35.Rf7+ Kg6 36.Qg8+ Kh6 37.Rh7#.
Promotion to rook or bishop.
Because the queen combines the powers of the rook and the bishop, there is rarely a reason to underpromote to either of those pieces. Doing so is occasionally advantageous, however, usually to avoid an immediate draw by stalemate if the promotion were to a queen. Of the two, the rook is usually preferable, since it is a and a greater material gain, especially when the player still has their original bishop of that square color.
Rook underpromotion.
In the position with White to move, Black threatens to capture White's pawn (which would be a draw). Promotion to a queen would result in a stalemate, whereas the move 1. g8=R! wins because White can force an elementary checkmate from the resulting position.
In the diagrammed position from the game Short–Dalyat, 2006 Irish Chess Championship, a promotion to queen would allow stalemate: 70...b1=Q?? 71.Qh3+! Kxh3 stalemate (or 71...Kg1 72.Qh1+!, and now the black king is forced to capture). Instead, the game concluded 70... b1=R! 
Less often, underpromotion to rook may be necessary not to avoid stalemate, but to "induce" it and thus save a draw in an otherwise hopeless position. To the right is an example from the end of a study by Frédéric Lazard. Black threatens checkmate by moving the king and playing ...Bf4. Promotion to queen does not work on account of 1.d8=Q? Bf4 2.Qd2+ Kf3 3.Qxf4+ Kxf4 and Black promotes either the c-pawn or the h-pawn. Promotion to rook saves the draw, however. After 1. d8=R! Bf4 2. Rd2 (if 1...Bxh2, then 2.Rd3+!), king moves by Black cause stalemate as the rook is absolutely pinned, whereas a queen would only be partially pinned and be able to move along the diagonal. Bishop moves along the c1–h6 diagonal by Black can be parried by attacking the bishop with the rook, so Black cannot make any progress: 2... Bg5 3. Rd5 Kf4 4. Rd2 Bh6 5. Rd6 Kg5 6. Rd2 is one possible continuation.
Bishop underpromotion.
In the position at left, the pawn must be promoted, as otherwise it is lost with a draw. Promotion to a queen or rook would pin the bishop, leaving Black with no possible move, resulting in a stalemate; promotion to knight threatens checkmate via 2.Nb6, but that is thwarted by 1...Bc7 2.Nb6+ Bxb6 3.Kxb6, with a drawn game by insufficient mating material. Promotion to bishop is the only winning move, threatening mate with Bb7 that the enemy bishop, being confined to dark squares, is helpless to prevent 1. c8=B! B\any 2. Nd7 B\any 3. Bb7# .
Less often, underpromotion to bishop may be necessary not to avoid stalemate, but to "induce" it and thus save a draw in an otherwise hopeless position. To the right is an example from the end of a study by Herman Mattison.
Both king moves lose quickly (they can be met by ...Rgg7, for example), so the pawn must be promoted. 6.b8=Q and 6.b8=R both lose to a capture on c8, and 6.b8=N, while leaving a stalemate after 6...Rgxc8??, loses quickly after 6...Rcxc8. This only leaves 6. b8=B!: since the c7-rook is now pinned, Black must either lose it with a theoretical draw or play 6...Rxc8 which, with a bishop on b8 rather than a queen or rook, is stalemate.
Underpromotion to knight or rook in practical play is rare, and to bishop is even rarer, but in composed chess problems such as this last example, it occurs more often. Perhaps the most famous example is the Saavedra position. Some cases can be quite spectacular: a study by Jan Rusinek, for example, sees White promoting to knight, bishop and rook in order to induce stalemate. An Allumwandlung is a problem where promotions to all four possible pieces occur. An extreme example is the Babson task, where underpromotions by Black are countered by matching underpromotions by White (so if Black promotes to a rook, so does White, and so on), White's underpromotions being the only way to mate Black in the stipulated number of moves.
In the 1972 game between Aron Reshko and Oleg Kaminsky, promotion to a queen or rook would allow 61...Qf7+ 62.Qxf7 stalemate. White could promote to a knight, but that would not be sufficient to win . White wins after:
If 62.Bc6 Qa2 63.Bd7 Qg8 64.Qxg8+ Kxg8 65.Kg6 also wins 
Black is in zugzwang for two moves.
In the actual game, White promoted to a knight. White won the game because of an error by Black .
In the 1938 (or 1933) game between Alexey Sokolsky and Grigory Ravinsky, promotion to a queen or rook would allow 66...Rc2+ 67.Ka1 (67.Kxc2 is a stalemate) Rc1+ with a draw by perpetual check. Promotion to a knight also draws after 66...Rc8! 67.Ra6 Rxa8 68.Rxa8 stalemate. However, the move 66. a8=B!, which was played in the game, wins for White, with the following main variations:
Insignificant underpromotions.
A majority of underpromotions in practical play are, as Tim Krabbé puts it, "silly jokes"—underpromotions made where there is no real need to do so, as the promoted pawn is immediately captured and thus its choice of piece is irrelevant. One high-level example was the game Shirov–Kramnik, Amber Blindfold, 2005. In the diagrammed position, Black played 25...e1=B+. This underpromotion is completely inconsequential as both it and 25...e1=Q+ force 26.Qxe1.
In 1932, a long game between Milan Vidmar and Géza Maróczy had been a theoretical draw for many moves, because of the opposite-colored bishops endgame. Two underpromotions to bishops occurred on successive moves by White:
The game was drawn on move 129.
Unusual situation.
An unusual situation occurred in a 1993 game between Anatoly Karpov and Garry Kasparov. Karpov was in serious time trouble, with one minute to make 16 moves. In this position, Kasparov captured the rook on d1 with the pawn on c2, and said "Queen!", indicating that the promoted piece was a queen. However, no queen was immediately available; it took some time for the arbiter to find a black queen. Kasparov said that if he had been more attentive, he would have promoted to a rook, which was available. Kasparov's clock was running while the arbiter was getting a queen, so he started Karpov's clock. Karpov immediately played 25.Qxe4 and Kasparov told him that he was in check, to which Karpov replied "From what? It might be a bishop on d1". At this point the clocks were stopped. The arbiter eventually found a black queen, the game was backed up to the position after 24...cxd1=Q+, and Karpov was given two extra minutes on his clock because of Kasparov's illegal move (since starting the opponent's clock signified the completion of his move, which was not possible without a piece to promote to; Kasparov disputes that he had made an illegal move). However, Kasparov soon won the game anyway .
Promotion in other games of the chess family.
Western chess variants.
Most variants of Western chess also include promotion in their set of rules. The promotion rule for these games is almost always very similar to that in standard chess, but slightly amended to match the rules of the given variant. In general:
These rules are not completely universal, but they apply to the majority of Western chess variants.
The first of the above generalisations means that a pawn on a larger board has to move further to be able to promote. Some (but not all) variants partially compensate for this by allowing the pawn to advance further on its initial move (e.g. in the 16×16-board game Chess on a Really Big Board, pawns can advance all the way up to the 8th rank).
The second and third of the general guidelines can lead to some unusual rules for certain games. For example, in Knightmate (where there are two kings but only one knight, and the objective is to checkmate the knight), the player may promote a pawn to a king, but not to a knight.
Regional variants.
The promotion rule in Western chess does not apply to all regional forms of the game. Most (although not all) regional variants do include some kind of promotion in their set of rules but it varies considerably depending on the region. In "chaturanga", which is widely considered to be the common ancestor of all variants of chess, pawns were promoted upon reaching the last rank of the board (like in Western chess); however, there is a dispute as to what the pawns could be promoted to. Some sources state that a pawn could only promote to a "mantri" - an early form of the modern-day queen, which could only move one square diagonally. Others claim that the pawn had to promote to the piece of the file on which it promoted (or the "mantri" if it promoted on the king's file), with a further stipulation that it was only allowed if the piece had been previously captured (otherwise the pawn could not promote at all and had to remain on the board as an immobile, "dead" piece). When the game was introduced to the Middle East as "shatranj" around the 7th century, the promotion rule was standardised to the former: i.e. a pawn could only promote to a "fers" (equivalent to "chaturanga"'s "mantri"). Both "chaturanga" and "shatranj" were then brought over to the western world and eastern Asia (as well as several other regions of the world), gradually evolving along the way. Pawn promotion has likewise evolved differently in various regions; as a result, each regional variant of the game now has different rules for promotion.
"Makruk".
In "makruk" (Thai chess), pawns begin the game on the third rank of the board (unlike "chaturanga", "shatranj" and Western chess, where they start on the second rank). They must promote upon reaching the sixth rank, i.e. the rank occupied by the opponent's pawns at the start of the game. Like in "shatranj", a pawn can only promote to a queen (which in "makruk" moves only one square diagonally).
"Sittuyin".
The promotion rule in "sittuyin" (Myanma/Burmese chess) differs from that in its predecessors in several ways.
The "sittuyin" board includes two diagonal lines, which connect the two opposite corners of the board. These diagonal lines mark the promotion squares: pawns standing on one of the marked squares on the opponent's half of the board can be promoted, but only to a queen (which moves like the queen in "makruk": one square diagonally). Promotion can only occur if the player's queen has been previously captured, i.e. it is not permitted to have more than one queen per player at any one time. Promotion is not mandatory and the choice to promote a pawn is at the discretion of the player.
Unusually for a modern chess game, in "sittuyin" promotion does not take place the moment one of the pawns reaches a promotion square. Instead, a pawn can be promoted only when it is already standing on one of these squares. It is unclear how this promotion is effected. Some sources claim that a player can promote a pawn instead of making a move (i.e. the promotion technically counts as a move of its own). Others state that a promoting pawn moves one square diagonally like a queen and then promotes to one within the same move, with a further restriction that such a move cannot give immediate check or capture the opponent's queen.
If a pawn passes through a promotion square without promoting, its chance for promotion is lost and it cannot promote again. A pawn that reaches the furthest rank cannot move at all and remains on the board as an immobile, "dead" piece.
"Shogi".
Uniquely among modern regional variants of the game, "shogi" (Japanese chess) does not restrict promotion to just the pawns. In fact, almost all pieces have the possibility to promote in "shogi".
In standard "shogi", the promotion zone consists of the three furthest ranks of the board (i.e. the three ranks occupied by the opponent's pieces at the start of the game). All except two of the eight types of pieces can promote; however, each piece can only promote to one particular piece; the player cannot choose its promotion like in standard chess. Two of these promoted pieces are only available by promotion, while the remaining ones do have an unpromoted equivalent (see "promotion in shogi").
Promotion in "shogi" is not mandatory and the choice to promote a piece is at the discretion of the player. This is important, as some pieces do lose some of their power upon promoting (e.g. a promoted silver general can no longer move diagonally backwards); thus there can be a legitimate reason to defer the promotion, even though theoretically they all gain more than they lose. The only exception to this rule is when a forward-moving piece advances so far forward that it would have no legal move on subsequent turns if left unpromoted (e.g. a pawn at the last rank) – in these cases promotion is compulsory. Promotion is, however, permanent – once a piece is promoted it cannot be demoted back into its original form until it is captured.
A piece can be promoted when it makes a move that starts and/or ends at the aforementioned promotion zone (i.e. when it moves either into, out of, or wholly within the zone). However, if the piece in question is dropped (see "drops"), it can only be dropped in its unpromoted state (regardless of where it is dropped and whether it was captured as promoted or not); it can then be promoted on subsequent turns as per above.
This means that, unlike standard chess where promotions are relatively uncommon, in "shogi" they occur multiple times in a single game and can play a crucial role in tactics and strategies.
"Shogi" variants.
Like standard "shogi", the majority of "shogi" variants have similar rules for promotion, where all but a few pieces have the ability to promote, but only to one type of piece each. In most (but not all) variants, the player's promotion zone is likewise bounded by the position of the opponent's pawns at the start of the game.
There are, however, some differences, especially in variants larger than "shogi" itself. For example, in the historical variants "chu shogi" and "dai shogi", among others, the option of promotion is more restrictive than in the standard game: a piece can promote normally as it enters the promotion zone, but if it makes a move out of or wholly within the zone, it can only promote if it also captures another piece. Also unlike standard "shogi", a forward-moving piece in these variants may be left unpromoted at the far end of the board; such a piece is left on the board as an immobile, "dead" piece. Furthermore, some pieces have different promoted states depending on the variant played (e.g. a silver general promotes to a gold general in "shogi" but to a vertical mover in "chu shogi" and "dai shogi").
Unique promotion rules apply to a variant called "maka dai dai shogi". In this variant, there is no promotion zone at all; instead, pieces can only be promoted upon capturing an opponent piece. Promotion is optional if the captured piece is unpromoted, but mandatory if the captured piece is promoted. This is particularly important, as many pieces "promote" to a far weaker piece, thus these pieces will often avoid capturing promoted pieces. This variant is also unique in that the king can promote as well: it promotes to a very powerful piece called the emperor, which can jump to any unprotected square on the board.
Unusually, many large variants (including "chu shogi", "dai shogi" and "maka dai dai shogi", as well as "sho shogi" which is a direct predecessor of standard "shogi") also have a piece known as the drunk elephant, which promotes to a prince. The prince has exactly the same movements as the king and is also a royal piece; this means that when a drunk elephant is promoted, the player has two royal pieces, and both must be captured in order to win the game.
"Xiangqi" and "janggi".
In complete contrast to the complex promotion rules described above, "xiangqi" (Chinese chess) and "janggi" (Korean chess), two closely related chess variants, have no promotion at all.
In "xiangqi", the only type of piece that changes its movement depending on its position is the soldier (equivalent to a chess pawn). At the start of the game, soldiers can only move and capture one square forward, but once they reach the opponent's half of the board, they can also move one square to the left or right. This is the closest thing that "xiangqi" has to actual promotion; however, it is not usually considered such, as even with these extra moves the soldiers remain relatively weak pieces, and their name does not change upon gaining these additional moves. A soldier that reaches the last rank can only move sideways.
"Janggi" does not have any moves that resemble promotion. Soldiers can always move one square forward or to the side, regardless of their position on the board. Like in "xiangqi", a soldier at the last rank can only move one square sideways.
Articles on promotions in certain endgames.
These articles involve endgames where the question is whether or not a pawn can be safely promoted: