At its simplest, a card is just that: a physical card, which may or may not have undergone any modifications. Its role in the game is both as itself and as whatever information it carries, which can be changed, erased or amended. The cards used vary widely in size, from the original Vis-Ed brand flash cards, to half or full
index cards, to simply sheets of
A7 sized paper. Cards may be created with any marking medium and need not conform to any conventions of size or content unless specified within the scope of the game. Cards have been made of a wide range of substances, and modifying the shape or composition of a card is entirely acceptable: the original Vis-Ed box still contains a card, created by
Plan 9 From Bell Labs developer Mycroftiv, to which a tablet of
zinc has been affixed with adhesive tape; the card reads "Eat This!... In a few minutes, the ZINC will be entering your system." Many cards have been created which demanded their own modification, destruction or duplication, and many have been created which display nothing but a picture or text bearing no explicit significance whatsoever. Some have been eaten, burned, or cut and folded into other shapes. The game does tend to fall into structural conventions, of which the following is a good example: A card consists (usually) of a title, a picture and a description of its effect. The title should uniquely identify the card. The picture can be as simple as a
stick figure, or as complex as the player likes. The description, or rule, is the part that affects the game. It can award or deny points, cause a player to miss a turn, change the direction of play, or do anything the player can think of. The rules written on cards in play make up the majority of the game's total ruleset. In practice, these conventions can generate rather monotonous decks of one panel cartoons bearing point values, rules or both. As conceived, the game is far broader, as it is not inherently limited in length or scope, is radically self-modifying, and can contain references to, or actual instances of, other games or activities. The game can also encode algorithms (trivially functioning as a
Turing machine), store real-world data, and hold or refer to non-card objects. ==History==