A pallet-dolly device convertible between a pallet and a dolly has a deck to which a set of dolly wheels are attached at a fixed height below the deck. A set of movable pallet skids are mechanically interlinked with the deck by a bistable skid displacement mechanism which assumes a first state biasing the pallet skids upwards towards a skid raised position and a second state in which the bistable skid displacement mechanism biases the pallet skids downwards towards a skid lowered position. Also described are embodiments allowing conversion from dolly to pallet by directly pressing downwards on a skid, and provision of a braked-dolly state through downward pressure of the skid against the ground and/or a skid-actuated wheel brake.