BALTIMORE SOLITAIRE, aka THIRTY-SIX, a solitaire card game variant that uses a standard deck of playing cards. In it, you are "double teamed" and must come up with a sum of cards from your tableau that exceeds that of your opponents. Has a few rules to get used to, but I post a number of photos to explain them. Once you start beating the game regularly, you can add in variations to increase the challenge.

Full instructions available at the "game" link above. Enjoy!