Rock Cube first appeared in Mega Man Battle Network, where it creates three stone cubes in random positions, while the chip Ice Cube creates a single cube in the panel in front of the NetNavi that used it. From Mega Man Battle Network 2 onward Rock Cube works like Ice Cube, creating a single cube in front of the user, and Ice Cube only appeared in one more game before disappearing. Up to two Rock Cubes can be present in the area at a time.
The Rock Cube offers protection against some attacks until it is destroyed. Rock Cube can also be used offensively when combined with other chips (such as Spreader), and it can be pushed in the enemy's direction with other chips (like Guts Punch and Air Shot) to cause 200 points of damage.
In Mega Man Network Transmission, alongside their original functions, Rock Cube and Ice Cube can also be used as temporary platforms. They disappear after 10 seconds or when destroyed. Both have 20 HP.