ECK (pronounced like “deck” without the ‘d’) is an abstract solo trick-taking game where the you play against the AI opponent ECK by attempting to collect trick cards by winning exactly the number of tricks shown on the available trick cards. The ranks are polygon shapes where increased complexity means increased trick value: line, triangle, square, pentagon, hexagon, octagon. The suits are colors red, orange, yellow, green, blue, and purple. So there are 6 ranks and 6 suits. There are also 6 circle cards, three white and three black, which act as trump cards.
The player draws a hand of 13 cards and plays one trick for each card. The AI opponent ECK is the remaining cards, and in each trick the player plays one card and ECK plays one card based on the rules for following suit.
There are 7 trick cards numbered 2,4,6,8,10,12, and 13/0. The player's goal is, at the end of each round, to have won exactly the number of tricks shown on one of the available trick cards, collecting that card if successful. Collecting 4 trick cards wins the game, though there are ways for ECK to win also.