Melee weapons in Dominions 5 come in three different types: slashing, piercing, and blunt. Each type has different effects when calculating damage.
Blunt weapons do 50% more damage when scoring head hits after the Protection value is deducted. They score 25% more damage toward shield destruction.
Slashing weapons do 25% more damage after Protection is deducted. They do 50% more damage toward shield destruction. If a slashing weapon scores a leg, arm, or head hit that costs a target greater than or equal to 50% of its hit points, that body part will be chopped off. If a head is chopped off, this will kill the target if it had a head that was required for it to stay alive. (For example, a hydra does not fit that description.)
Piercing weapons reduce Protection by 20% prior to any calculation. This is the same mechanic as the Armor-Piercing ability, except that Armor-Piercing reduces Protection by 50%.
Two-handed weapons add 125% of Strength to damage.
Underwater effects: slashing and blunt weapons have an attack penalty equal to weapon length underwater while piercing weapons do not. If a weapon does both piercing damages as well as another type, the underwater penalty is halved. Flails have an additional penalty of -1.
A weapon may be able to inflict more than one type of damage. If so, it has an equal chance of doing each type of damage but will only do one of them during that attack. For example, the short sword does both slashing and piercing damage. It has a 50% chance of doing one of these. If it does not do piercing, it will do slashing, but never both.
Note that these weapon types apply to all sorts of weapons, not just maces, swords, and spears. A spider’s venomous fangs can do piercing damage, for example.