Seven Skulls

Seven Skulls is a dice-based gambling game popular in the frozen north, especially among the Frost Giants. The game is played with seven twelve-sided dice: two per player, and three common dice. Each player puts one coin in the pot before rolling his pair of dice behind a screen, and must pay a second coin if he wants to continue after rolling. If both players have paid to continue, the first player (or a tournament official) calls out "skulls roll!" and rolls the three common dice. At this point, players may bet up to three coins, call the other player's bet, or raise a bet by an equal, double, or triple amount. Once the final bet has been called, the dice are shown, and the winner takes the pot. Play continues until one player is out of coins, with first chance to bet and "first player" status alternating between the two players.

Dice are compared based on the three highest-scoring dice among the five available (a player's 2 personal dice and the 3 common dice). Dice normally score their face value, but if a player has a triple, each die is treated as one number higher, and those are his scoring dice (so three 7's are scored as 8-8-8.) The third-highest die is compared first, with the highest taking the pot. If this is a tie, the second-highest die is compared, and finally, the highest die. If all three dice are tied, the pot is split.

Scoring Examples:
A has 12-6. B has 9-8. Common dice are 11-10-9. A scores 10-11-12, B scores 9-10-11. 10 beats 9, so A wins.
A has 12-6. B has 9-8. Common dice are 11-7-5. A scores 7-11-12, B scores 8-9-11. 8 beats 7, so B wins.
A has 12-6. B has 11-6. Common dice are 11-5-3. A scores 6-11-12, B scores 6-11-11. 12 beats 11, so A wins.
A has 12-6. B has 8-8. Common dice are 11-8-3. A scores 8-11-12, B scores 9-9-9 due to the triple. 9 beats 8, so B wins.
A has 12-6. B has 11-8. Common dice are 11-8-7. A scores 8-11-12, B scores 8-11-11. 12 beats 11, so A wins.
A has 12-6. B has 11-8. Common dice are 11-8-8. A scores 8-11-12, B scores 9-9-9 (rather than 8-11-11). 9 beats 8, so B wins.
Note that, if the common dice are a triple, both players automatically score the same and the pot is split.

Terminology and slang:
"Skulls" - the twelve-sided dice.
"Drop" or "drop the skulls" - allow the other player to take the pot; analogous to folding in poker.
"Goblin" - low-scoring die.
"Dragon" - high-scoring die.
"Ettin" - paired player dice.
"Big Ettin" - a pair of 12's for the player dice.
"Dog" - a triple, named after the three-headed Cerebrus.
"Big Dog" - a triple that includes the highest common die. Guaranteed to be the best hand.
"axe" or "axe mark" - dice with a wide split in value, like 12-3 or 11-1.