The average Orcish cleaver or dub is a big, crude affair much like the Ore on the blunt end of it. This is the standard armament for Orc foot troops and characters, and is carried instead of a normal hand weapon. Orcs refer to such weapons as 'choppas'. Such a chunk of metal would he difficult for a human to wield in one hand but Ors are muscle-bound beasts with fists as big as a man's head (and only marginally more dexterous).
An Orc warrior on foot armed with a single choppa adds +1 to his Strength in the first round of a combat when he charges. This bonus does not apply if a weapon is carried in each hand, or for Boar, Chariot or monster riders - in such eases the weapon's natural brutishness is cancelled out by the difficulty of wielding it.
The Choppa bonus applies to character models on foot that are armed with a single ordinary non-magical choppa. It does not apply to individuals armed with magic weapons as they receive the appropriate magical bonuses instead.
TO put the matter beyond any shadow of a doubt – only Orcs on foot benefit from choppas – not Goblins, not mounted Orcs, not modes on chariots, not small boys called Kevin, not Gerbils, not anything else ever, never, not ever, OK!
Note that the bonus armour save for using a hand weapon and shield does not apply to an Orc wielding a choppa. Foot models with a choppa in each hand () do get the normal +1 Attack for having two 'hand weapons', though they lose the +1 Strength on the charge.