Bone Cards were magical devices used in the card game Bones. They allowed the wielder to capture and contain creatures, who were then rendered on the face of card as a skeletonized version of themselves. The wielder could then control the monster, using them in a battle against other Bone trainers.
The method of capture worked almost exactly like a [REDACTED]: the card would be struck against the desired creature. It would then wiggle three times, and then, on a successful capture, it would light up, revealing the victory. The creature contained within could be released as they normally were before being captured, not skeletonized in any way. These creatures would not retain any memories of their time in the card, and existence seemed to halt for them when they were trapped.
Each card had a symbol of the monster type on it, and the monster contained within would receive a bonus if their type matched the card type.
Cards could be deployed at range, as demonstrated when Rowan Grey shot an arrow at Dr. Varmus Gremp, who was then captured successfullysource.
Skud Derringer received six blank Bone Cards from the young trainer Dodge Grabbit after they rescued one of his powerful cards from the nefarious Ballista Twins. Three of the cards were reserved for Rowan, Lahni Caplain, and Toby Treacletart, while the other three needed to be filled with powerful creatures. The party decided to go after Rick the Beholder, Dr. Varmus Gremp, and Pyre the Dragon, though in the case of Dr. Gremp, they ended up trading him away to Braenth of Barovia in exchange for a Astral Dreadnaught.