The POW Block is an item found in all Paper Mario games. It is capable of doing 2 damage to all enemies. In turn, it flips them over, rendering them helpless. In Paper Mario: The Thousand-Year Door, this item is the only method used to defeat Bristles until certain Badges such as the Spike Shield are acquired. Also useful when fighting large groups of Koopa Troopas, since it will flip them over rendering them unable to attack in most cases. In Paper Mario, the same effect occurs but only targets ground-based enemies.
In Super Paper Mario, the POW block is an expensive Item that can deal heavy damage if properly executed by shaking the Wii remote up and down. It can also be cooked to make the Megaton Dinner. One of the Sammer Guys fought is named Block of Pow.
In Paper Mario: Sticker Star, POW Blocks appear as stickers, taking their design from how they have commonly appeared since Mario Bros. When used, a POW Block appears, which Mario hits twice to inflict damage to enemies and occasionally inflict the Crumpled status. Unlike the previous iterations, however, the POW block affects only foes on the ground.
In Paper Mario: Color Splash, POW Blocks appear as Battle Cards, with the same behavior as they had in Paper Mario: Sticker Star. POW Blocks also appear outside of battle in Kiwano Temple, where one is used to flip some spikes, and Violet Passage, where they can be hit with a cannonball in order to collect coins.
In Paper Mario: The Origami King, POW Blocks return as items that can be used in battle. They serve the same purpose, although Mario can only carry three at a time.