Buildings in Warcraft III can be very tough and take a while to destroy. There are also several upgrades and abilities, which allow buildings to stay around even longer. Players need a way to destroy buildings with these added challenges in a quick amount of time. That is where siege units come in! Each race has certain units and abilities which are designed to destroy buildings faster. Players should bring siege units along when they assault an enemy town.

Siege units do 150% damage vs. buildings.

Siege Unit damage will hurt your own units if they are close to where a Siege Unit fires.

Siege Units' Role
Siege Units are viable counter units to use in combat against enemy armies. People should generally have 1-2 Siege Units with their army to help them crack into an enemy base.

Repair
Bring workers to repair mechanical Siege Units during battle. Use healing to restore the health of organic Siege Units.

Spotting
Siege Units need the fog of war to be revealed so they can fire from their maximum distance. You can, however, use Attack Ground to fire without revealing the enemy. This can be more challenging when dealing with ramps going to high ground or nighttime. Use things such as Huntress Sentinel, Priestess of the Moon Owl, Night Elf Shadowmeld/Hide, Crypt Fiend and Carrion Beetle Burrow, Far Seer Far Sight, Mortar Team Flare, Witch Doctor Sentry Wards, Crystal Balls, Goblin Lab's Reveal, Undead Shades, and flying units to reveal the area ahead of the Siege Units with little risk of attack.

[ Click to Enlarge - 140 KB ] A Night Elf player uses a Huntress with Hide to spot for the two Glaive Throwers.

Building Upgrades
Some upgrades can make buildings even tougher or more dangerous.

Humans

Improved Masonry - Increases the armor of buildings by 1 and the hit points of buildings by 20%
Advanced Masonry - Further increases the armor of buildings by 1 and the hit points of buildings by an additional 20% of the base hit points of the building.
Imbued Masonry - Further increases the armor of buildings by 1 and the hit points of buildings by an additional 20% of the base hit points of the building.

Spiked Barricades - Surrounds Orc buildings with spikes that damage melee attackers. Deals 4 damage per attack.
Improved Spiked Barricades - Further increases the amount of damage inflicted on melee attackers by an additional 6.
Advanced Spiked Barricades - Further increases the amount of damage inflicted on melee attackers by an additional 6.
Reinforced Defense - Upgrades Burrows and Watch Towers so that they have Fortified armor.

Night Elves

Nature's Blessing - Increases Ancient Protector's armor to 3 and all other Ancients' armor to 7.

Humans, Orcs, Undead - The Human Peasant, Orc Peon, and Undead Acolyte can use their Autocast repair ability to repair buildings while they are being attacked. Activate the repair ability by right-clicking on it. Now surround the buildings with workers repairing the buildings.
Night Elves - Night Elves can use Wisps to Heal their buildings or Ancients. Night Elves can also use Eat Tree to give their buildings more health.

Siege Units
The following are units designed to destroy buildings. Use these when you attack enemy towns and expansions.

Humans

Mortar Team
Siege Engine
Flying Machine (with Flying Machine Bombs)

Orcs

Demolisher
Raider
Troll Batrider

Undead

Meat Wagon
Frost Wyrm (with Freezing Breath)

Night Elves

Glaive Thrower
Chimaera (with Corrosive Breath)
Mountain Giant (with War Club)

Orcs

Far Seer - Earthquake

Undead

Frost Wyrm - Freezing Breath prevents buildings from being used to train units.
Lich - Death and Decay, a very good building destroyer.

Night Elves

Demon Hunter - Metamorphosis

Neutral

Naga Sea Witch - Tornado
Beastmaster - Stampede