The self-cocking crossbow is a special type of compound crossbow - a bolt-action crossbow - first developed during the late 7th century AEKE. The weapon operates on a simple principle - rather than just one crossbow bolt being readied to be shot, the weapon comes with a magazine ethat is meant to hold 4-5 crossbow bolts. When the "trigger" is pushed up to fire the weapon, the magazine itself is simultaneously raised up. After the bolt got fired, a sideways handle can be used to pull the one crossbow bolt which is raised to "surface level" back to the back of the weapon, simultaneously pulling back the string.
This intricate design comes with both advantages and disadvantages. Best suited for urban warfare, the weapon was first used by Dark Elven mobsters in the underground and Etrand. King Bryant I of Etrand made attempts to introduce the weapon to the Etrandish military, but - discouraged by the military experts who claim that the weapon is ill-suited for pitched battles in the open - he did not go through with it. King Orlonius I of Etrand is currently raising a new mercenary force equipped with self-cocking crossbows.
The weapon's name, "self-cocking crossbow" is rather misleading - the crossbow does not cock itself automatically. It is best described as a bolt-action compound crossbow: the projectile still has to be manually pulled by an addition handle to the back of the weapon to be ready to fire, but it is very easy compared to that of other crossbows.
This weapon is unrelated to the pump-action repeating (automatic) crossbows employed by the Ling Empire, although it may have been inspired by them.
The self-cocking crossbow is best described as a bolt-action. Pushing up the trigger serves two functions: the string was "let off", firing the loaded projectile, and at the same time, the magazine holding the other bolts was raised upwards, allowing the crossbowman to load the next one by pulling back a sideways handle, which pulled back the bolt with itself, pulling the string along with it. Then the handle could be let go, and the crossbowman could fire again by pushing up the trigger.
The most fundamental advantage of the self-cocking crossbow is speed. Since the weapon comes with a magazine holding four or five crossbow bolts, the crossbowman can fire multiple times before being forced to reload. Between the current and the next bolt, the crossbowman only has to wait until the bolt gets fired - after that, he can immediately pull the sideways handle to get the weapon ready to fire again.
This makes the weapon well-suited for urban warfare. Mobile crossbowmen can hide behind cover - or a pavise - to fire multiple times before having to reload, and flee to a safer place in case their cover is not deemed safe enough to reload.
The biggest disadvantage of the self-cocking crossbow is the short range of the weapon. Being a crossbow inherently means sacrificing range and speed for power and accuracy. The self-cocking crossbow remains accurate, but sacrifices even more of the range for speed and power. While the weapon is deadly in the close range - such as in a house, or in urban warfare - it is practically useless in the open field, and usefulness remains limited in siege battles as well, especially for the attacking side.
Critics of the weapon also point out that the philosophy of the weapon defeats the purpose of crossbows - crossbows are slow because they are reloaded in intricate manners that minimize the need for muscle power. The self-cocking crossbow on the other hand is cocked by hand, which means that manufacturers have to make a choice: either make the weapon "available" only to physically strong users, like longbows, or sacrifice power and accuracy to make the weapon usable by everyone.
Another weakness of the weapon lies in the loading mechanism - the emptier the magazine gets, the stronger the crossbowman has to push up the trigger. If the magazine is fully loaded, but the crossbowman pushes up the trigger as if he would in case of only one bolt remaining, the magazine gets pushed up too much, accidentally loading multiple bolts, which leads to erratic behaviour. This lack of consistency makes the weapon considerably more difficult to use by conscripts, as crossbowmen have a hard time being careful about how strongly they pull the trigger during the heat of battle.
Last but not least, the weapon is somewhat expensive, since all the metal parts are made out of dense materials: the crossbow needs to be compact and handheld, but to have sufficent strength, it must not be lightweight. To make it both compact and heavy at the same time, it needs to be made out of dense materials, which are usually expensive.
Evidence for the weapon's existence goes to the 7th century at earliest, to the various Dark Elven clans. The weapon became a favourite of the Dark Elven mafia in Grandfolk, due to its optimization for urban warfare.
Until the crowning of King Orlonius of Etrand in 809, on military has ever adopted the weapon, although chronicles claim that the weapon did in fact see usage in the 718 Etrandish succesion crisis by the forces loyal to Mythela and Bryant. King Bryant was also very fond of the weapon and loved using it for hunting. He had ambitions to adopt it to the Etrandish military as early as the 720's, but military experts pursuaded him not to do that, rationalizing that the weapon's disadvantages and limitations make it ill-suited for military use.