In Karnickel, each player places his rabbit on the circular train track made of eight interchangeable tiles, sets the train engine on its start space, then takes turns rolling the custom dice. After you roll, set any die that shows the "train" out of play, then count up how many times each of the player colors appears on the remaining dice; you must move one of the rabbits (yours or another player's) clockwise around the track the full number of spaces. You then pass the rabbit dice to the next player. Players take turns, each time rolling only the dice passed to them and hopping the rabbits from tile to tile, trying to land on the tiles where they will be able to collect the most carrots.
When a player rolls only trains, the rabbit hopping has to stop as the train is ready to move! That player rerolls all seven dice, counts up the number of trains rolled, then moves the train that many spaces around the track. Every rabbit on a tile that the train moves through is scared away by the engine and hops off the track, failing to collect any carrots this time. All rabbits still on the track after the train moves — either because the train didn't reach them or because they were on one of the two tunnel tiles — get to grab 1, 2 or 3 carrots...or maybe lose one — exploding carrots are a risk!
Everyone then hops back onto the track, and the next player rolls all the dice to start a new round of play. Whoever has the most carrots when one player has at least eight carrots wins!