|Cost|| 80 Food,|
A great use for Petards is neutralizing enemy buildings or siege units near the player's castles. They are also an excellent choice for quickly breaching walls, taking only two to destroy a stone wall (assuming they have the Siege Engineers upgrade). However they are not cost effective in large numbers since they can only be used once.
The primary use of gunpowder during the Middle Ages was as a propellant in firearms and cannon, but it eventually found use as an explosive also. Explosive charges, called petards, could be used to damage or blow down castle gates and other obstructions. The word petard comes from a French word for breaking wind. In very dangerous situations, an armored man would carry the petard to the point of attack and light the fuse. If the fuse malfunctioned or the charge went off prematurely for any reason, the bombardier was “hoisted by his own petard,” which explains a phrase still used today when a plan or operation backfires.