Dansk
Der kan deltage to spillere, hvoraf den ene bruger mørke og den anden lyse pinde. Spillerne skiftes til at anbringe en pind i et hvilket som helst hul, som i forvejen ikke er optaget. Det gælder om for hver af spillerne at få etableret en ubrudt kæde af pinde mellem spillernes to sider. Kæden kan sno sig ud og ind på alle tænkelige måder. Et eksempel på en vindende kæde kan ses på forsiden af instruktionen. Hullerne i hjørnerne af spillet tilhører begge spillere. Spillet kan ikke slutte uafgjort, eftersom den ene spiller kun kan blokere den anden ved at færdiggøre sin egen kæde.
Piet Hein fandt på spillet CON-TAC-TIX®, mens han gik og overvejede den berømte fire-farve-teori, der gælder inden for topologi. Teorien, der endnu ikke er bevist, går ud på, at fire farver er tilstrækkelige til at udforme ethvert landkort således, at der ikke er to lande med samme farve, som grænser op til hinanden. Piet Hein præsenterede spillet i 1942 på Niels Bohr Institutet. Samme år offentliggjorde en førende dansk avis spillet, og det blev hurtigt utrolig populært i Danmark (under navnet Polygon). Der blev solgt plader, hvorpå man kunne spille med en blyant, og i mange måneder kørte avisen en række CON-TAC-TIX®-problemer med præmier for de bedste løsninger. Albert Einstein, som var dybt interesseret i spil, havde siden 1948 Piet Heins CON-TAC-TIX®-spil stående på en hylde på sit kontor.
English
CON-TAC-TIX® is played on a diamond-shaped board by two players. Twoopposite sides of the diamond are marked black; the other two sides arewhite. The holes at the corners of the diamond belong to either side. Oneplayer has a supply of black pegs; the other, a supply of white pegs. The players alternately place one of their pegs in any one of the holes, provided the hole is not already occupied by another peg. The objective of Black is to complete an unbroken chain of black pegs between the two black sides- White tries to complete a similar chain of white pegs between the white sides. The chain may freely twist and turn. The players continue placing their pegs until one of them has made a complete chain. The game cannot end in a draw, because one player can block the other only by completing his own chain.
The game of CON-TAC-TIX® occurred to Piet Hein while he was contemplatingthe famous four-colour theorem of topology. The theorem, as yet unproved, it that four colours are sufficient to make any map so that no two countries of the same colour have a common boundary. Piet Hein introduced the game in 1942 at the Niels Bohr Institute. The same year a leading Danish newspaper published an account of the game; it soon became enormously popular in Denmark (under the name of Polygon). Pads on which the game could be played with a pencil were sold, and for many months the newspaper ran a series of CON-TAC-TIX® problems, with prizes for the best solutions. Albert Einstein who was passionately interested in games had since 1948 Piet Hein’s CON-TAC-TIX® on a shelf in his study.
