A robotic palletization/depalletization system is disclosed. In various embodiments, data associated with a plurality of items to be stacked on or in a destination location is received, and a plan to stack the items on or in the destination location is generated based at least in part on the received data. The generating the plan includes determining a source location from which to pick the item based at least in part on (i) an attribute of the source location, and (ii) a state of a platform or receptacle on which one or more items are to be stacked.