7 or 11 or Doubles
This game is best played with at least three people, although two players are acceptable. The original game rules include drinking challenges, but underage players or players uninterested in drinking could modify this game to include other challenges.
You need two dice for this game. Choose one person to start; they simply toss the dice and read the number. If the dice show a sum of seven, 11 or doubles the roller gets to choose a person to drink. This person must drink until the roller then rolls another seven, 11 or doubles. Modify this game to include physical challenges such as hopping on one foot, doing handstands, spinning in circles or tossing a Hacky Sack with your feet. You can even create rules that turn this game into a kind of truth or dare, with or without the alcohol.
Drawing Dice
This game can be played with two or four people; it works best with an even number. Each person or team of two gets two dice. Each team also agrees on a picture to draw according to the numbers that roll up. For instance, if drawing a person a sum of two could mean an eye, a sum of 3 a nose, and so on with more body parts. The team that finishes its creature or person faster, wins. This game is best played with children learning to add, though it can be modified for older children; simply instruct them to multiply or divide the numbers instead.
Teens and adults could add another twist to this game by adding physical challenges. For instance, a sum of four may mean a hand, but a three-and-one combination means the player must draw with his feet while a two-and-two combo means he must draw with his mouth.
Threshold
This is another very simple game that works best with four people if you want to drink. If not, two or three is just as fun. Toss two dice in a cup with a coin and let one person shake it. Another person in the group guesses heads or tails. If the guesser is correct, he chooses someone to drink the number of shots on the dice. If not, the guesser must drink the shots.
Modify this game for all ages and preferences by replacing the drinks with tasks. Assign each possible number and combination with a task like hopping up and down the stairs on one foot, walking a straight line on tip-toe, or carrying a spoon in your mouth with a piece of ice on it for one minute without dropping it.