Siege engine

Siege engine was a term for an expansive variety of weaponry and temporary structures that were designed for the purpose of siege warfare. Those skilled in the building and operation of siege engines were known as siege engineers.

Weaponology
Siege engines were typically used in offenses against walled cities and thus were rare to non-existent in areas of Toril that lacked such structures, such as Chult. Beyond land, siege engines were often found mounted on ships and used in naval combat. And beyond Toril itself, many spelljammers utilized weapons that were derived from siege engines.

Bombardment Engines
Bombardment engine was a term for any siege engine that was designed to hurl large missiles. Some had little to no accuracy, firing their projectiles indirectly high into the air, and thus had to be pointed in general directions rather than at specific targets. While others fired in low, flat curves and thus were more accurate.
 * Ballista: A stationary form of siege weapon that resembled that oversized crossbow, mounted on a swivel. They typically fired heavy, spear-like missiles, though could be made to fire round shots of metal or stone. Of the bombardment engines they were fairly accurate and had a trajectory that was relatively flat.
 * Bombard: A large pipe of wrought iron or bronze that shot large, but relatively light weight, stone balls or cast iron "cannonballs" in a high arch.   They could be found in wildspace, though only rarely due to often being impractical compared to ballistas or catapults. They could also be found used on ships on Toril, being one of the largest weapons on the planet to require smokepowder charges, and were believed to have been the creation of Thayvians. However, they were quite rare, expensive, and dangerous to use.
 * Catapult: A massive variety of siege engine, usually consisting of a lever made from a flexible material mounted on a sturdy frame. They were capable of hurling rocks and other heavy objects high into the air, deriving this power from tension. They could be further separated into heavy and light catapults, which were different in size and had different limits to what they could hurl.
 * Mangonel: A type of siege engine similar to ballistae.
 * Trebuchet: A massive variety of siege engine similar to catapults. They relied upon gravity and the potential energy of their heavy missile loads, a lever and counterpoise system, to fire from great distances.

Crushing Engines
Crushing engines were siege engines that were designed to breach gates or walls through various means, such as impact, but did not utilize missiles.
 * Battering ram:
 * Bore: also known as a sow, was a siege engine designed for use against stonework. They were similar in design to a suspended battering ram, consisting wheeled gallery with a central mechanism (usually a log), capped with a large metal screw bit, that was suspended from its roof beams with slings. This manner of suspension allowed the mechanism to turn about its axis. operated by pulling back the mechanism and letting it swing into the target, much like a wheeled battering ram. Some bores instead had stakes of metal or wood driven into the mechanism along their length, which acted as handles for operators to manually rotate it against the target. The weight of bores varied from.

Miscellaneous

 * Arcane: a variety of magical siege engines in the 15 century DR that were used by Thay, based defensively around the Thayan Plateau, and by the floating Netherese citadel Kolthunral. They were designed to hurl various type of arcane energy, such as fire, force, and lightning.
 * Flame cannon: A siege engine that was designed to hurl casks of alchemist's fire.
 * Greek fire projector: A metal tube that was designed to fire everburning oil.
 * Siege tower: Massive mobile wooden towers. They were typically built as a beam frame standing  tall, with a ladder on its back or interior,  with wheels or atop rollers. Some were built with drawbridges and a partially enclosed deck at their top.  They were designed to be moved up against an enemy structure and allow troops to scale over while under the cover of the tower.

Notable Siege Engines

 * Kezef bane, a magical siege engine that was used by the Knights of Samular to turn the tide of the Second Troll War.

Groups

 * Both members of the City Guard and Navy of Waterdeep had many members skilled in siege engineering.
 * The Company of Hunnar was a mercenary company that specialized in siege warfare and utilized a wide variety of siege engines.

Nations & Settlements

 * The Citadel of the Respected had three massive siege engines stationed atop its towers that were capable of hurling small boulders against those who threatened the city of Muluk.
 * The Citadel of the Raven housed many great siege engines within its armory, which were used to slay two out of three dragons that attacked the citadel in the month of Eleasis, 1356 DR.
 * Cormyr.
 * Upon the cliffs overlooking Port Llast were siege engines capable of hurling boulders.
 * The kingdom of Scardale notably had siege engines in Harborwatch Keep in defense against pirates.
 * The walled Thayan city of Surthay had siege engines within many of its towers.
 * The nation of Turmish and its capital city of Alaghôn had siege engines in their standing army, which their founder Dempster Turmish chose not to utilize when besieging the walled city of Hlondeth in 145 DR.