This is a gambling game for two or more players. Each player chooses dice from a pool, such that the number of sides selected is at most twenty. The players then roll the dice, and the player with the highest score wins an amount of money equal to the difference in the points total multiplied by the point value.
Before play begins, agree a point value. This is how much each point difference in score is worth to the winner. Then agree on a dice pool. The pool of dice should contain d4, d6, d8, d12 and d20, at least one of each, and between 6 and 10 dice per player. Players can agree to vary any of these restrictions on the pool, if they so wish.
Determine which player can pick first from the pool. They should choose dice with sides that totals at most twenty. The second player should then pick from the remaining dice, again choosing dice with a total of at most twenty sides.
Both players roll their dice, and add up the total score they gain. The loser pays the winner the points difference multiplied by the point value.
Return all dice to the pool.
Then the player that picked dice second picks new dice, followed by the other player. They roll and and the loser pays the difference.
This ends the round. If players agree, then can continue, stop playing, or change the point value.
Andrew and Ben agree to play Twenty Sides. They set a point value of one token per point. The have a dice pool of 1d20, 2d12, 4d8, 6d6 and 6d4
Andrew is chosen to pick first, and decides to take the easy option of taking the single twenty sided die.
Ben picks two of the d8, and a d4.
They roll the dice, Andrew scores 11, but Ben does badly, only gaining a total of 6. Ben pays Andrew 5 tokens.
Now it is Ben's turn to select dice, and he takes a d12 and a d8. Andrew did well on the previous throw, and decides to taken 5d4, trying to avoid a big loss by selecting dice that will most likely score near their expected total.
Ben does better, scoring 14, but Andrew only scores 12. He pays Ben 2 tokens.
At the end of the round Andrew is 3 tokens ahead. The players can continue the game, change the point value, or stop.
It is possible to extend the game to include more players, by increasing the size of the dice pool. Play proceeds as normal, all players select a set of dice from the pool, they throw in turn, and all losing players pay the Winner from each throw.