Is There Chess on Mars? by Taylor Kingston "We have a game on Mars similar to chess, very similar. And there is a race that plays it grimly with men and naked swords. We call the game jetan." John Carter, Warlord of Barsoom. In 1912 Edgar Rice Burroughs sold his first novel, A Princess of Mars. Though he would become best known for his Tarzan books, Burroughs (1875-1950) was an extremely prolific author (some would say far too), who set his pulp-fiction adventure stories not only on earth (or in the case of the Pellucidar series actually inside the earth), but in a variety of extra-terrestrial locales, such as Mars, the moon, and Venus. Of these the Mars novels, or Barsoom series as they are known ("Barsoom" being the Martian name for Mars), were always my personal favorite. Combining astronomer Percival Lowell's then widely accepted notion of a canal-crossed, inhabited Mars, with elements of European knighthood, the American Wild West, imperial Rome, ancient Egypt, legends of other lost civilizations, and his own vivid imagination, and framing them in an ethos derived in large part from medieval chivalry and British imperialism, Burroughs created colorful, exotic settings and cultures in which manly sword-wielding heroes fought against black-hearted villains and bizarre, ferocious beasts for the honor and love of stunningly beautiful, scantily clad women (who, incidentally, reproduced by laying eggs). The Chessmen of Mars, 5th of the 11 Barsoom novels, came out in 1922. In plot it was a stock adventure odyssey/love story; Burroughs was essentially an imaginative hack who wrote the same story with minor variations dozens of times over. The interesting minor variations this time were, one, the "Kaldanes," a race of super-intelligent bodiless heads, and two, a chess-like game called "jetan." Though the novel deals little with the play of jetan itself (it was used mainly as a stage for a gladiatorial spectacle), Burroughs nevertheless provided a full description of the game and its rules in an appendix. Reading The Chessmen of Mars as a teenager in the early 1960s, I tried the game, making my own jetan set and playing with friends. This was partly because, at the time, I could hardly beat anyone at chess, and so thought my chances at jetan would be better (they were!). However, it was also because the game itself has considerable intrinsic interest. It is doubtful that Burroughs was himself a serious chessplayer; for example in Chessmen's prologue he makes the dubious claim that "[There is a] theory ... that phenomenal chess players are always found to be from the ranks of children under twelve, adults over seventy-two or the mentally defective - a theory that is lightly ignored upon those rare occasions that I win." I suspect he was just an average untrained dabbler, or perhaps, like Sinclair Lewis when he wrote Cass Timberlane, Burroughs learned the rudiments of chess merely to be able to use it in his novel. Nevertheless, he managed to create a fairly interesting and workable game, though one not without flaws. Whenever reasonable I have represented a jetan piece by the chess piece most like it, but none move exactly as any chess piece; the reader should keep that clearly in mind. The board is 10x10, the colors orange and black. This reflects the game's mythic origin in legends of a war between the yellow people (though it was never explained why then orange pieces) of north Barsoom and the black people of the south, and explains the position of the dark pieces on the lower (i.e. southern) ranks and the light pieces on the upper (northern) ranks. (Unlike with chess, suspicions of racist overtones in this have some basis. Burroughs' writing occasionally reflected the prejudices of his times, racial war was sometimes depicted, and political correctness was not a priority. However, this being a chess magazine, we will concentrate on the game.) I will now discuss the pieces' names and moves. Quotes are from the Chessmen appendix; keep in mind that by "straight" Burroughs meant an orthogonal move, i.e. north, south, east or west, like a chess Rook. The Thoat (an 8-legged horse-like Barsoomian animal), moves "2 spaces, one straight and one diagonal in any direction." The diagram shows the Thoat's possible moves by the squares marked "x". This is quite similar to a chess Knight, with two exceptions: the Thoat cannot leap intervening pieces, and when not blocked it can also access the four squares orthogonally adjacent, for example here, where it stands on f6, by going to f7 then g6. Burroughs was not explicit about whether the straight move must be done first and only then the diagonal, or either order was permitted. If the former, and there were another piece on, say, f7, this Thoat could not reach e6, e8, f6 or f8. The Panthan (meaning "soldier of fortune" or mercenary), moves 1 space in any non-backward direction. Though like a pawn the least powerful piece, it has significant differences: there is no 2-square initial move, it captures the same as it moves (as do all jetan pieces except the Princess), and there is no promotion. This has major implications in all 3 phases of the game: in the opening, slower contact of opposing forces; in the middlegame no locked Panthan chains or weak doubled or isolated Panthans; and in the endgame no "queening" or blockading of "passed Panthans." To paraphrase General MacArthur, old Panthans never die, they just shuffle along the 10th rank. The Warrior (represented here by a checker piece) moves "2 spaces straight in any direction or combination." Again, as with the Thoat, Burroughs was unfortunately somewhat unclear; he never said, either in the rules appendix or in the novel, whether "2 spaces" meant 2 and only 2, or, either 1 or 2 squares. I tend to a "strict constructionist" interpretation: 2, no more, no less. Generally in board games what is not expressly permitted is forbidden. Furthermore Burroughs was a somewhat wordy author; he never used 5 words when 10 would do (a contemporary example would be Lev Khariton, who uses 5 paragraphs when one sentence would do). If he had meant "1 or 2" I think he would have said so. However, some jetan players take the looser interpretation and allow 1 or 2 square moves. In this diagram therefore, and in the others that follow, I show the "strict interpretation" moves by "x" and the extra moves allowed by the liberal interpretation with a "+". Either way, the Warrior field of force has a diamond-shaped pattern. It reaches the diagonally adjacent squares by moving first one direction, then at right angles, i.e. zig-zagging, what Burroughs calls a "combination" move (not to be confused with a chess combination). Note that though it moves orthogonally, under the strict interpretation the two-square rule keeps it as color-bound as a diagonally moving piece. The Padwar (lieutenant, represented here by a checker king) moves "2 spaces diagonal in any direction or combination." As the diagram shows, this results in a square pattern (or under the liberal interpretation two concentric squares) of force. Under the strict interpretation, the Padwar's move is very much like the Bishop's in the medieval version of chess, before the modern rules came about in the 1500s. Comparing the Padwar to the Warrior, another argument in favor of the strict interpretation can be deduced. In the Barsoomian military, as on earth, a lieutenant outranks an enlisted man. Yet if the liberal rule is used, the Warrior, with the ability to move on two colors, would be the stronger piece. It seems doubtful Burroughs intended this (though he may not have given it much thought!). The Dwar (captain), moves "3 spaces straight in any direction or combination." This is the first of what could be considered "major" pieces. Assuming again that "3 spaces" means only 3, the Dwar creates a double-diamond pattern. Under the strict interpretation, the immediately adjacent squares are reached by a series of right-angle moves, e.g. here f7 might be reached by moving g6-g7-f7. The presence of pieces on e6 and g6 would make f7 unreachable, because no jetan piece may touch the same square twice in one move (e.g. here f5-f6-f7 is forbidden). Note that unlike the Warrior and Padwar, the Dwar can access both colors, but under the strict interpretation, like a chess Knight, it changes square color with each move. The Flier (also called "Odwar" meaning General), moves "3 spaces diagonal in any direction or combination; and may jump intervening pieces." This creates a pattern of two (or, liberally, three) concentric rectangles. The Flier is obviously bound to squares of one color, but the leaping ability increases its power. One can readily see that jetan requires one to visualize in a rather different way than chess. Unlike chess pieces, which (except for the Knight and King) radiate extended lines of force, jetan pieces, especially under the strict interpretation of the rules, have confined patterns of force, some (such as the Flier's or Dwar's) of a snowflake-like complexity, especially under the strict version of the rules. These can be hard to perceive at a glance, and the presence of other pieces alters and complicates matters further. Of course, a novice feels the same way about chess; no doubt with practice one can attain quick sight of a jetan board as well. The Chief, moves "3 spaces straight in any direction, straight or diagonal or combination." Even though it cannot overleap obstacles, this is a tremendously powerful piece; in an open position it controls up to 48 squares, 48% of the board. This holds for either interpretation of the rules, and makes it more powerful even than a chess Queen, both absolutely (the Queen covers a maximum of 28 squares) and in relative terms (28/64 = 43.75%). However, Burroughs set two important caveats on the Chief: the game is lost if it is captured by the opposing Chief, and drawn if it is captured by any other piece. The Princess moves exactly as the Chief, with two enhancements: she can leap over intervening pieces, and for an emergency she is allowed once in the game a 10-square move, called "the escape." However, like the chess King she may not move into check, nor may she ever capture any piece (reflecting the chivalric cliche of the helpless "damsel in distress"). The game is won when the Princess is captured, though as with checkmate she is never actually removed from the board; a player moves his attacking piece to the same square as the opposing Princess. Thus, unlike chess, there are two ways to win: capture the Princess, or take the opposing Chief with your Chief. One might ask, how the latter could be done, as in most cases placing one's Chief in position to capture his counterpart would naturally expose him, suicidally, to capture first. However, there is at least one way. This diagram shows in simplified form how a skewer tactic could do the trick. Orange, to move, plays his Chief to f5, attacking the black Princess. She must move, thus exposing her own Chief to capture. Note that Orange must not play his Chief to d5 or e5, as both squares are within reach of the black Chief. I would add that another tactic, the pin, would also work, except that it is probably against the rules. In this position Black's Dwar on c4 is pinning the orange Chief, as he cannot move off the c-file without exposing the Princess to check. Now by moving his Chief to b3, b4, d3, e4, or e5, Black would be in position next move to capture his paralyzed counterpart and win. However, is Orange truly paralyzed? Could his Chief then take Black's, because it happens before the Princess is taken? Burroughs' rules leave it unclear whether such a pin is absolute. My view is that the Chief capture, by occurring first, would take precedence, and thus Orange could capture and win. A somewhat similar situation occurs in chess, as when a Bishop, pinned because it is shielding its own King from check, still prevents the enemy King from moving onto its diagonal. Assuming the pin to be absolute, note that in the above diagram Black would not want to play the Chief to d5 or f5, as that would place him within reach of the orange Flier. Orange would then take the black Chief and, by rule, escape with a draw. This rule that the game is drawn whenever a lesser piece takes the Chief is disliked and disregarded by some jetan enthusiasts, who then treat the Chief like any other piece, except with regard to the opposing Chief. Relative material values can be estimated by comparing the number of squares each piece can control: Panthan 5; Warrior 8 (under the strict interpretation)/12 (liberal interpretation); Padwar 8/12; Thoat 12 (either); Dwar 20/28; Flier 20/28; Chief 48. Reducing the Panthan to a value of 1, these come out to: Warrior and Padwar 1.6/2.4, Thoat 2.4, Dwar and Flier 4/5.6, and Chief 9.6. Still, further questions arise, but sufficient practical experience to answer them is lacking. In chess, for example, the Knight and Bishop are considered fairly equal, though the Knight at any one time controls at most 8 squares to the Bishop's 13. Similarly, one wonders is the Dwar or Flier the stronger piece? The Padwar or Warrior? Does the lack of promotion for Panthans make them worth even less? Jetan has many other complexities which, due to a lack of organized serious play, remain unplumbed. For example, returning to the opening array (see diagram) one wonders what correct opening principles would be. Should one rush the pieces out, or play hedgehog style, creeping forward behind a slowly advancing phalanx of Panthans? Should the minor pieces (Thoats, Warriors, Padwars) come out before the majors (Dwars, Fliers, Chief)? Should one develop Dwars before Fliers? In the middle game, are mating attacks feasible, or is the Princess so mobile she can always escape? Is there any meaningful endgame, since no promotion of Panthans is possible? Burroughs did not trouble himself with such questions. If he had, the logical course in Chessmen of Mars would have been for the super-intelligent, super-rational Kaldanes (spiritual forebears to Star Trek's Mr. Spock) to analyze jetan. Perhaps realizing that probably would not sell many copies, Burroughs introduced a new variable: jetan with living pieces who duel to the death (as Edward Lasker said, "chess for blood"). In such a game, captures do not involve the simple removal of a piece from the board; rather the two "pieces" fight with swords, the survivor remaining in possession of the square. Thus in such a game swordsmanship can greatly outweigh jetan mastery. That is definitely the case in the one jetan game described at any length in The Chessmen of Mars, in which both sides make moves which ordinarily would be blunders. The novel's hero, Gahan, Jed (prince) of Gathol, is Chief of the Black against U-Dor, henchman of the evil O-Tar, Jeddak (king) of Manator, in a game for possession of Tara, kidnapped Princess of Helium, daughter of the great Warlord, John Carter. The diagram shows the position after Orange's 2nd move. By moving his Odwar (the Manatorians, who have no flying machines, use that name) in such a brutally simplistic fashion he sets Black a dilemma: either move the threatened Princess, in which case Gahan would admit a certain cowardice and lack of confidence in his own swordsmen, or attempt capture by his own Odwar, thereby risking immediate loss of the game should the black player lose the duel. Gahan plays Od1-g4 (or in the full descriptive notation Burroughs employs, "Chief's Odwar to Princess' Odwar's fourth!"). Needless to say, the black Odwar is victorious, after a short but tense duel. Though full details are lacking, a few moves later a position something like this arises. The black Chief Gahan has gone in direct pursuit of his enemy. U-Dor tries to stave off the inevitable by sending in the Panthan (f8xe7), but Gahan, like most of Burroughs' heroes a superb swordsman, makes quick work of him. Gahan then advances to the orange Chief's home square and bests him in a classic duel, administering the coup de grace "with a blow that cleft him to the chin." We do not recommend this style of play for the home version of the game. As far as actually playing at home, I have found no maker of jetan sets. The closest established board game I know of is shogi, Japanese chess, with a 9x9 board. One might be able to jury-rig another row of squares and paste suitable letters or symbols on the flat shogi tiles. As a teenager I fashioned fairly easily a home-made set with hand-colored squares on cardboard and balsa wood pieces of my own design, but we had to be very careful: a sneeze, or even a heavy sigh, could scatter them like leaves. What purports to be jetan software is offered by a company called Tommy's Toys; for $6.00 it can be downloaded from their web-site www.tommystoys.com. However I found it to be a crude, unreliable version of the game, more like an early 1980s DOS-based PC chess program prototype. It would occasionally make illegal moves. The only other mention of jetan I've been able to find on the Internet is on several web-sites devoted to Burroughs' works (probably where some Chess Cafe readers found their quiz answers). However these only described the game; they did not offer any sets or organized activity. For those who might want to try the game themselves, I would recommend the following alterations to correct jetan's ambiguities and shortcomings: (1) Experiment with both the liberal and conservative interpretation of the move rules and decide which seems to work best. (2) Eliminate the rule that the game is a draw if a Chief is captured by a non-Chief. This should no more be a draw than if a chess Queen is captured by a Rook. (3) Allow promotion of Panthans reaching the 10th rank to any piece except a Chief or Princess. So that's jetan in a nutshell. Considering that Burroughs, unlike Edward Lasker, John Scarne or other game inventors, was not a professional gamesman, and that he created jetan mainly to serve as a literary device, it is surprisingly well-designed. Still, it has not been popular (though I would welcome feedback from readers who may know otherwise). Perhaps it had a brief heyday at the time of Chessmen's publication, and there was a mild flurry of interest in the early 1960s when the Barsoom novels were reprinted in paperback by Ace and Ballantine, but today jetan appears to be as passe as belief in Martian canals. Too bad, because, as I hope I have shown here, it is an interesting game with many unexplored mysteries.