Cardgame!, or the Multi-Purpose Cardboard Open Gaming System, is a copy-left system, based on six-sided dice and using a simple point-buy build.

Some Example Cards

unformatted rules text:
Let me tell you a bit about my own little lots-of-d6's game engine. It takes all teh good bits from wargames, Magic: the Gathering of Other People's Money and 'tactical' RPG's such as D&D. Everything has a clear point cost, and nothing is unbalanced. There are four combat stats which determine the amount of dice you may roll to hurt one another, and a multitude of special abilities. Any game, be it Tolkienesque fantasy or hard Sci-Fi, can be constructed and supported by this game. And you can create a single character, a squad or even a 'theme deck'; Sky's the Limit.

Every card (or character sheet) (or unit) has a Number for Attack; this number represents the amount of dice the Thing represented by the card may roll for Aim and helps determine Initiative, and costs an equal number of points. Strength represents the Damage roll dice and the Range the Thing's weapons have, measured from the center of the card. Dodge governs Evasion rolls and the distance the Thing may travel per turn, also called Speed. Protection represents Protection dice and the amount of Resistance the Thing has against radiation and/or disease.

Special Abilities may further adjust the actual value of all Stats; examples to follow. Basic Combat: First, Initiative order is determined from highest to lowest. In case of ties, the Thing with the higher value/cost goes first. A Thing whose 'turn' comes up may move and shoot once, in any order it's Owner/Creator chooses. Shooting involves rolling the attackers Aim vs the defenders Evasion. If the attacker wins, roll attackers Damage vs defenders Armour. If the attacker wins, the attacking Thing's Owner/Creator may reduce one of the defending Thing's stats by one. A Thing with all stats at Zero that gets hit must be removed from the 'battlefield' (and since it has no Evasion or Armour left, every shot hits). Special Abilities Because having one stat determine both Range and Damage dice is totally boring, having 'special abilities' that increase one or the other adds to the fun. As seen in the above example, special abilities can add to one of the four stats or to just one of the eight substats. These 'bonus dice' don't have to be removed via hits like regular stats/dice. Having 'Epic' stats costs 1 extra point per stat that's six or higher, since 6 cannot lose to 1. Regeneration doubles the cost of the Thing, and 'regenerates' one point/die per 'turn' of its Owner/Creators choice. Extra Hit Points: Lost first when hit. Dominate: gain temporary control of target card with value X or lower (X points)

'Auras' that increase or decrease the stats of other Things are also bought on a 1-for-1 basis. A variable bonus or penalty would cost twice as much. For example, 2 points would buy +2 to a stat, +4 to a substat or +1 'to any stat of your choice'. Healing ability would cost 2 points (per point healed each 'turn'), but healing another Thing or the Healing Thing itself would take up the Healing Thing's entire 'turn'.

A variant rule on Special Abilities is to not have them cost 'value points' but Energy Points. Divide the normal point cost of abilities in two to get the energy cost, and calculate card value/cost from stats only. In a MtG-like game, players would have to agree on the amount of energy they get each turn. This energy would then be used to 'summon' cards/Things and pay for Special Abilities.