A foundation is a pile of cards where the cards are stored in some, ordered way. Frequently cards are ordered from Ace, up in sequence, until the King, with suited cards. Normally, there are one foundation by suit and deck. So, if the game is played with one deck, there are four foundations, if played with two decks, eight, and so on. Most of the games are finished succesfully, when all cards are in foundations. In some games, base of the foundation is diferent from Ace. For instance Canfield or Terrace. Base is taken from the first card entering in the foundation. When base card is not Ace, cards are ordered up in sequence until the King, and then follows the Ace. In some games, base of foundation is different for each foundation, as in Interregnum. In this cases Rank base is showed inside the foundation. Foundation position is showed with a shadow containing the symbols for each suit:
In some games cards can be ordered in some different sequence, for instance with same suit , or different color cards, as in Spanish Patience, or sequence ordered regardless suit or color, as in Numeric and related games. When foundation base is not Ace, and is the same for all of them, base Rank is showed beside the first foundation. For instance, Canfield:
In some games, as Terrace games, when game starts there is an ? beside the foundations. En algunos juegos, como por ejemplo los de tipo Terrace, al comienzo del mismo aparece un ? al lado de los cimientos, meaning thet the Rank base is not set, and the first card entering will be the base Ranks. This has to be the first action in the game.
Cards can be moved to foundations by drag and drop the card over the foundation target, or simply with a long touch (Android version) or double click (PC version) over the card. Card is moved to the first foundation possible.
When a card is dragged over a foundation, foundation darkens if the card is admissible in that foudation (is in the right sequence for this game). if it is no darkened, move is not possible. If card is dropped and move is not possible, card returns to the original position.
In some games, when cards are moved to foundations cannot return to other elements of the game. Other games admit this movement.
Most of the games, but not all have foundations. When present game allways is won by moving all cards to the foundations. When not exist game is won in some other way.
It's very important check allways the correct wsy of building the foundations.