US Patent 7566057 Stacking puzzle and method for playing same

A stacking puzzle has a substantially horizontal stationary base, a plurality of stacks of playing pieces of progressively larger diameters having bores therethrough and a plurality of upwardly extending pegs. The pegs include shared pegs for receiving playing pieces from two of the stacks and unshared pegs for receiving playing pieces from only one of the stacks. An object of the puzzle is to displace each of the stacks in the fewest number of moves by moving the playing pieces one at a time from peg to peg. A playing piece cannot be placed over a playing piece of the same or smaller diameter and a playing piece from a stack not associated with a particular unshared peg cannot be placed on that unshared peg.