Wands, staffs, and rods are well-established weapons in the world of Eberron. Similarly, arcane artillery doesn’t employ any sort of physical projectile, relying solely on magical energy—but rather than a small weapon one person can easily carry, arcane artillery refers to a variety of larger arcane foci that can increase the range and area of magical attacks. Likewise, the war employed magical explosives such as blast disks that could wreak devastation by triggering a previously stored spell.

As a general rule, the everyday magic of the Five Nations encompasses spell effects of up to 3rd level; while 4th- and 5th-level effects exist, they are rare and remarkable. This means that effects like wall of force could be seen on the battlefield, but were exceptional and rarely deployed, while blasts of fire and lightning were more common.

Operating Arcane Artillery

While a specially trained spellcaster must operate arcane artillery, more than one person can assist with its operation, allowing a team to prime, aim, and fire in a single round.

All attack rolls and saving throws are based on the spellcasting ability of the operator firing the weapon. When arcane artillery is used to target someone at long range, any attack roll has disadvantage and any saving throw against the spell effect has advantage.

Using these weapons requires specialized training, similar to that of an artificer or magewright; someone trained to operate arcane artillery is generally called a bombardier. A typical bombardier may use the magewright stat block, but they also know one or more spells that they’re only able to cast using a focus—such as a siege staff or long rod. So an Aundairian specialist might be able to produce cloudkill through a focus, but not cast the spell on its own. Bombardiers don’t use spell slots when casting these spells; instead, they prime the weapon using a dragonshard solution known as the breath of Siberys.

Breath of Siberys

Wondrous item, common
Arcane artillery requires a powerful surge of magical energy to fuel the attack. Wizards and other spellcasters can prime arcane artillery by expending a spell slot, but bombardiers don’t have spell slots. Instead, a bombardier charges the weapon by using the breath of Siberys—a small globe containing a highly refined solution of dragonshards held in a suspended state. While priming arcane artillery, the operator crushes the breath of Siberys against an engraved brass plate; the sphere dissolves and the weapon is charged.

House Cannith has been developing traditional staffs that can be charged using breath of Siberys. It takes an action to dissolve the breath on the charging plate, restoring 1d4 charges to the staff. Cannith artificers are working to adapt other charged items to use breath of Siberys.

Siege Staff
Huge arcane artillery (staff)
Armor Class: 15
Hit Points: 120
Siege staffs, the primary form of arcane artillery, are made of wood—typically around fifteen feet long—engraved with mystic sigils and inlaid with dragonshards.

Activating a siege staff takes three actions: one to prime the staff; one action to aim it; and one action to release the spell. There are several basic models, each of which serves a different purpose. When activated, it produces one of the following effects, determined by its model:

Blast Staff. This model was typically used to bombard massed troops or villages, unleashing a wide burst of energy. It has a range of 1200 feet and targets all creatures within a 60-foot-radius sphere. This attack deals 3d6 force damage, or half on a successful Reflex save.

Force Staff. This model releases focused blasts of pure energy. Developed late in the war, these were primarily used to target fortifications, warforged titans, and airships. It has a range of 2400 feet and deals 8d10 force damage.

Focus Staff. This model amplifies the spells cast by a spellcaster. Any spell that requires an attack roll or saving throw can be cast through this model of siege staff. The range is magnified by a factor of 5, with a long range of up to 10 times the spell’s standard range. The spell’s area of effect is doubled. If the spell normally affects a single target, it instead affects a 20-foot-radius sphere; if the spell normally requires an attack roll, targets must instead make a Reflex saving throw. On a successful save, the target takes half damage and suffers no other effect.

Long Rod
Large arcane artillery (rod)
Armor Class: 15
Hit Points: 40
A long rod is a more portable version of a siege staff, measuring around 8 feet long. Including the stand required to brace it, it weighs close to 350 pounds.

It takes five actions to set up a long rod, and the same to tear down for transport. Once set up, it takes one action to prime the rod, one to aim it, and one to fire it.

Any spell that requires an attack roll or saving throw can be cast through the long rod. The range is magnified by a factor of 3, with a long range of up to 6 times the spell’s standard range. The spell’s area of effect is increased to 150%. If the spell normally affects a single target, it instead affects a 10-foot-radius sphere; if the spell normally requires an attack roll, targets must instead make a Reflex saving throw. On a successful save, the target takes half damage and suffers no other effect.

Enhanced Artillery
While arcane artillery is a powerful force, there’s still a place for mundane siege engines that use physical projectiles. The ballista, mangonel, and trebuchet are all common forms of artillery, seen on both the battlefield and on warships. However, just as a Thrane archer may have used an enchanted bow, the siege engines of the Last War are enhanced with magical power.

Animated Engines. A siege engine can be partially animated, speeding its use. Generally, an animated engine loads itself while the crew aims it, requiring only two actions to fire an animated ballista or three to use an animated mangonel. House Cannith also manufactured fully animated siege engines, capable of self-aiming. Such an engine required the same number of actions to aim and fire as a crewed engine, it simply had no need of a crew. However, these engines could only follow simple instructions and had little ability to adapt, requiring clear, absolute orders to be effective: “Continue to attack the north tower until it is destroyed.”

Cannons. A cannon is a weapon that can inflict significant bludgeoning damage at great distances. The most common form of cannon is the elemental cannon produced by the gnomes of Zilargo, which uses the essence of a bound earth elemental to project stone cannonballs with tremendous force; Zilargo began supplying Breland with these weapons toward the end of the Last War. While Cannith and the Five Nations experimented with other cannon models, the siege staff typically filled this role on the battlefield.

Enchanted Ammunition. Ballista bolts and mangonel missiles are often enchanted with spell effects that trigger when the bolt strikes its target. This effect is in addition to the standard damage inflicted by the siege engine.
• Explosive ammunition affects a 30-foot-radius sphere centered on the impact of the bolt. Any creature in the area must make a DC 15 Reflex saving throw, taking 3d6 damage on a failed save, or half as much damage on a successful one. Typically, explosive ammunition deals fire damage, igniting flammable objects that aren’t being worn or carried. However, Karrnathi deathbolts deal negative energy damage and only harm living creatures, while Thrane Tira’s tears deal positive energy damage.
• Summoning ammunition conjures creatures around the point of impact. Aundairian firestones produce a temporary flaming sphere that randomly rolls around the area of impact. Zil binders developed a more powerful form of this ammunition which casts conjure elemental on detonation, but it is extremely costly and rare.
• Panic stones force all creatures within a 90-foot-radius sphere centered on the impact of the stone to make a DC 12 Will saving throw. Any creature that fails the saving throw drops whatever it is holding and becomes frightened for 1 minute. Frightened creatures must use the Dash action to move away from the panic stone. If an affected creature ends its turn more than 90 feet away from the panic stone, it can make a Will saving throw. On a successful save, the effect ends for that creature.