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.

Literature

 * In Starlight and Shadows Forgotten Realms trilogy Fyodor carries a sword which is not sharp at all and so big he have a problem swinging it, even though he's an apprentice smith and looks accordingly. He can use it esily in berserk rage, however. Later he explained that a blunt sword is.

Video Games

 * Guan Ping wields an over-sized broad sword in Dynasty Warriors. Thing is, though, is that it often does more blunt force trauma 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.
 * Adray's sword in Star Ocean 3 never leaves the hilt, as the attack animation has Adray use the hilt and scabbard to attack, but never the blade itself. Either that's just how he fights, or the blade is too dull for slashing/stabbing. In any event, the blade is only used as a bludgeon.
 * Poo's Sword of Kings in Earthbound never seems to be used for slashing/stabbing, it's either just there to give him an attack boost like an accessory, or he just uses the flat parts to attack with.
 * Dwarf Fortress has training weapons - these are made of wood and have great contact areas (i.e. are extra-blunt), which allows sparring without serious accidents (at least, if the participants wear armor).

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.
 * Butter knives and any knife made out of extremely dull materials to begin with generally make poor weapons overall and qualify as this trope by default. Knives made of stone or ceramic can avert this, as it is possible to give them very sharp edges, but this would especially apply to knives made of soft plastic or safety scissors, which are blunted by design.
 * Most axes used in combat were partial aversions of this trope. While the geometry of axeheads generally made it bad idea to make the weapon slashing specific, it did have some utility when cutting off limbs at the joints. However, many axes used in combat were meant to also be used to shatter armor, with the bladed end being used to focus the attack against weak spots on the enemy armor.
 * Any shield with bladed attachments is mostly used as a defensive bashing weapon, with the bladed parts merely used to increase the damage done to lightly armored opponents.