Bludgeon Blade

Some blades, to be frank, suck at the "blade" part, often working much better as a blunt weapon for one reason or another. Sometimes this is by design, but sometimes, this is just Epic Fail on the part of those who made the blade for stabbing or slashing.

Video Games

 * Guan Ping wields an over-sized broad sword in Dynasty Warriors. Thing is, though, is that it often does more blunt force trama damage according to the animations than it does by bladed damage.
 * Cloud Strife's Hardedge blade from Final Fantasy VII looks more like an abbreviated girder with a hilt than any type of blade, and even though it makes a cutting noise ingame, in reality, you'd be better off using it to club your enemy to death.
 * In The Elder Scrolls V: Skyrim, axes are grouped under maces as blunt weapons, as according to an in game manual, the battle drill and technique are considered nigh identical, despite axes having a blade. In fact, with the exception of one kill animation, most hits with axes use the exact same motion and impact as maces.

Real Life

 * Can happen to any bladed weapon if you let it get dull enough.
 * In medieval times, any sword was effectively this if used against an opponent wearing plate armor. In fact, most sword users practiced a technique call 'half-swording", which meant the sword was aimed at points between the plates or in-between the jointed sections of the plate. Attacks directly on the plate turned even the sharpest sword into a pathetically ineffective club.
 * This trope was intentionally invoked in medieval tourneys, where blades were blunted on purpose, as the point was show how kickass you could be in a real fight, not actually to kill the opponent.
 * Halberds were basically designed more for dismounting riders from horses, using the blade as a hook, and as a polearm with a blade on the end for utility purposes. The blade did see use at times, but it was mainly a blunt weapon with long reach, with the blade used to compliment it's other attributes.