The "Pulsar" expansion to the game Urknall consists of a detachable DIN A6 sheet included in a Mücke Spiele flyer. The sheet displays an image representing a pulsar on one side and the expansion rules on the other.
At the beginning of the game, one of the four 3er-celestial bodies is placed on the pulsar. With four players, an additional free 1er-celestial body is placed on the pulsar so that the celestial body there becomes a 4er-CB.
In a pulsar, the ownership of the elements can change before the active player throws the die. This uncertainty is rewarded because at the end of the game the asset markers placed in the pulsar get twice as many points.
The active player, before throwing the die, sees whether there are unoccupied elements on the pulsar and, if so, the 3er-celestial body in the pulsar is rearranged as follows: a-b-c becomes b-c-a, but the asset markers remains were they laid, so the ownership structure on the celestial body changes (with four players, the 4er-CB changes from a-b-c-d to b-c-d-a).