Are the cards that have a grey, stone background frame. These represent your character’s training and preparation for the fight. Foundations will stay on the board once you play them. You can use them for their text abilities or to help you play other cards.

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Modifying A Control CheckEdit

Normally, if you fail a control check when attempting to play a card, that card is discarded and your combat phase ends (unless failing to play a response card). If, however, you have any ready Foundations in your staging area, all is not lost. After you fail a control check, you may commit a number of ready Foundation cards in your staging area equal to the amount by which you failed the control check. You may count your Character card as a Foundation and commit it instead or as well. If you commit enough cards in this way, you pass the control check, your card is brought into play, and you may continue with your Combat Phase. When you are paying a cost, you may commit your character card in place of a foundation.

UFS rules