The Knaves (invaders from outer space) are infiltrating this planet, and you must prevent them from landing! We have discovered a way to disrupt their cloaking mechanism using a modulated laser pulse. By increasing the amount of modulation, you can cause their ships to overload and self-destruct. But, be careful: if you apply too much modulation, then the Knave will fully de-cloak and retreat to try to land somewhere else. Knave Defender is a solitaire game where cards from a deck are assigned to one or more piles. The goal is to make the sum of the cards in a pile equal 21 (using Blackjack math) within a limited amount of time.