The following is designated as Open Game Content per the Open Game License.
This cursed item appears to be a standard silver piece of local origin, and is found with other mundane coins. The enchantment on the coin draws the nearest person to pick it up, upon which that individual is affected by the coin's more sinister power. The accursed is rendered unable to keep track of how much there is of a given thing. This includes, but is not limited to, coins, ammunition, rations and even living creatures. The coin clouds the part of the victim's mind that controls his ability to do even the most basic mathematics. Once per round, the amount perceived fluctuates by 20-80 percent (2d4x10, roll a d6 to determine of the amount increases or decreases. Odd numbers increase the amount, even number reduce. The GM rolls these dice in secret.). In combat with four or more foes of the same type, the owner of the coin suffers a -2 to all attack and damage rolls as they are unnerved by the changing number of opponents. The owner may also run out of key items due to overestimating how much they have at a given time, and will have difficulty making purchases due to being unable to keep track of funds. However, unlike other cursed items, the coin's curse will leave the individual if the coin is leaves the victim's possession. The curse is them passed on to the new owner.