Crossbow A crossbow is a type of bow consisting of a horizontal limb assembly mounted on a stock that shoots projectiles , called bolts or quarrel s . The medieval crossbow was called by many names , most of which derived from the word ballista , a torsion engine resembling a crossbow in appearance . Historically , crossbows played a significant role in the warfare of East Asia , Europe and the Mediterranean . The invention of the crossbow caused a major shift in the role of ranged weaponry among armies , as the traditional bow and arrow had long been a specialized weapons system which required a considerable degree of lifetime training , physical strength and expertise to operate with any degree of efficiency ; in many cultures , despite being usually drawn from the common class , bowmen were considered a separate and superior caste , as their archery skill - set ( similar to many horseman cultures ) was essentially developed from birth and impossible to reproduce outside a pre - established cultural tradition , which many nations lacked . In contrast , the crossbow was the first projectile weapon to be simple , cheap and physically - undemanding enough to be operated by large numbers of conscript soldiers , thus enabling virtually any nation with sufficient coin to field a potent force of ranged crossbowmen with little expense beyond the cost of the weapons themselves . This led to the ascendancy of large mercenary armies of crossbowmen ( best exemplified by the Genoese crossbowmen ) , and the eventual death of the heavily armored aristocratic knight as armies became progressively dominated by conscripts equipped with increasingly - powerful ranged projectile weapons . In modern times , although largely supplanted by firearms in most roles , crossbows are still widely used for shooting sport s , hunting , and when shooting in relative silence is an important consideration . Construction . A crossbow is a bow mounted on a stick ( called a tiller or stock ) with a mechanism in it which holds the drawn bow string . The earliest designs featured a slot in the stock , down into which the string was placed . To shoot this design , a vertical rod is thrust up through a hole in the bottom of the notch , forcing the string out . This rod is usually attached perpendicular to a rear - facing lever called a trigger or " tickler " . A later design implemented a rolling cylindrical pawl called a " nut " to retain the string . This nut has a perpendicular center slot for the bolt , and an intersecting axial slot for the string , along with a lower face or slot against which the internal trigger sits . They often also have some form of strengthening internal " sear " or trigger face , usually of metal . These " roller nuts " were either free - floating in their close - fitting hole across the stock , tied in with a binding of sinew or other strong cording , or mounted on a metal axle or pins . Removable or integral plates of wood , ivory or metal on the sides of the stock kept the nut in place laterally . Nuts were made of antler , bone , or metal . Bows could be kept and ready to shoot for some time with little effort , allowing crossbowmen to aim better . The bow ( called the " prod " or " lath " on a crossbow ) of early crossbows was made of a single piece of wood , usually ash or yew . Composite bows are made from layers of different material — often wood , horn and sinew — glued together and bound with animal tendon . These composite bows , made of several layers , are much stronger and more efficient in releasing energy than simple wooden bows . As steel became more widely available in Europe around the 14th century , steel prods came into use . The crossbow prod is very short compared to ordinary bows , resulting in a short draw length . This leads to a higher draw weight in order to store the same amount of energy . Furthermore the thick prods are a bit less efficient at releasing energy , but more energy can be stored by a crossbow . Traditionally the prod was often lashed to the stock with rope , whipcord , or other strong cording . This cording is called the " bridle " . The strings for a crossbow are typically made of strong fibers that would not tend to fray . Whipcord was very common ; however linen , hemp , and sinew were used as well . In wet conditions , twisted mulberry root was occasionally used . Very light crossbows can be drawn by hand , but heavier types need the help of mechanical devices . The simplest version of mechanical cocking device is a hook attached to a belt , drawing the bow by straightening the legs . Other devices are hinged levers which either pulled or pushed the string into place , cranked rack - and - pinion devices called " cranequins " and multiple cord - and - pulley cranked devices called windlass es . Variants . Crossbows exist in different variants . One way to classify them is the acceleration system , while another is the size and energy , degree of automation or projectiles . A recurve crossbow is a bow that has tips curving away from the archer . The recurve bow ' s bent limbs have a longer draw length than an equivalent straight - limbed bow , giving more acceleration to the projectile and less hand shock . Recurved limbs also put greater strain on the materials used to make the bow , and they may make more noise with the shot . Multiple bow systems have a special system of pulling the sinew via several bows ( which can be recurve bows ) . The workings can be compared to a modern compound bow system . The weapon uses several different bows instead of one bow with a tackle system to achieve a higher acceleration of the sinew via the multiplication with each bow ' s pulling effect . A compound crossbow is a modern crossbow and is similar to a compound bow . The limbs are usually much stiffer than those of a recurve crossbow . This limb stiffness makes the compound bow more energy efficient than other bows , but the limbs are too stiff to be drawn comfortably with a string attached directly to them . The compound bow has the string attached to the pulleys , one or both of which has one or more cables attached to the opposite limb . When the string is drawn back , the string causes the pulleys to turn . This causes the pulleys to pull the cables , which in turn causes the limbs to bend and thus store energy . Other types of compound bows use either ( one or both ) cam shaped or eccentrically mounted pulleys in order to provide a " let off " , such that the archer is not holding against the maximum draw weight of the bow while trying to aim . But in a crossbow the string is held back mechanically , so there is no advantage in providing a let off . Therefore , compound crossbows generally use only pulleys that are both round and concentrically mounted , in order to capture the maximum available energy from the relatively short draw length . The smallest crossbows are pistol crossbows . Others are simple long stocks with the crossbow mounted on them . These could be shot from under the arm . The next step in development was stocks of the shape that would later be used for firearms , which allowed better aiming . The arbalest was a heavy crossbow which required special systems for pulling the sinew via windlasses . For siege warfare the size of crossbows was further increased to hurl large projectiles such as rocks at fortifications . The required crossbows needed a massive base frame and powerful windlass devices . Such devices include the oxybeles . The ballista has torsion spring s replacing the elastic prod of the oxybeles , but later also developed into smaller versions . " Ballista " is still the root word for crossbow in Romance languages such as Italian ( " balestra " ) and Spanish ( " ballesta " ) . The repeating crossbow automated the separate actions of stringing the bow , placing the projectile and shooting . This way the task can be accomplished with a simple one - handed movement , while keeping the weapon stationary . As a result , it is possible to shoot at a faster rate compared to unmodified version . The Greek Polybolos was an ancient repeating ballista reputedly invented by Dionysius of Alexandria in the 3rd century BC . The Chinese repeating crossbow , Chu Ko Nu , is a handheld crossbow that accomplishes the task with a magazine containing a number of bolts on top . The mechanism is worked by moving a rectangular lever forward and backward . The weapon was mainly used as a weapon against lightly armored soldiers , since it shot small bolts that were often dipped in poison . A bullet crossbow is a type of handheld crossbow which rather than arrows or bolts shoots spherical projectiles made of stone , clay or lead . There are two variants ; one has a double string with a pocket for the projectile , and the other has a barrel with a slot for the string . Projectiles . The arrow - like projectiles of a crossbow are called bolt s . These are much shorter than arrows , but can be several times heavier . There is an optimum weight for bolts to achieve maximum kinetic energy , which varies depending on the strength and characteristics of the crossbow , but most could pass through common chain mail . In ancient times the bolts of a strong crossbow were usually several times heavier than arrows . Modern bolts are stamped with a proof mark to ensure their consistent weight . Bolts do not have fletch ing , i . e . feathered ends like those commonly seen on arrow s . Crossbow bolts can be fitted with a variety of heads , some with sickle - shaped heads to cut rope or rigging ; but the most common today is a four - sided point called a quarrel . A highly specialized type of bolt is employed to collect blubber biopsy samples used in biology research . Most modern crossbows are designed to shoot arrows instead of bolts . Crossbow arrows are of similar construction to ordinary bow arrows , just shorter in length because of reduced power stroke . Crossbows can also be adapted to shoot lead bullets or stones , in which case they are called stone - bows . Primarily used for hunting wildfowl , these usually have a double string with a pouch between the strings to hold the projectile . Accessories . The ancient crossbow often included a metal grid serving as iron sights . Modern crossbow sights often use similar technology to modern firearm sights , such as red dot sight s and telescopic sight s . Many crossbow scopes feature multiple crosshairs to compensate for the significant effects of gravity over different ranges . In most cases , a newly - bought crossbow will need to be " sighted " for accurate shooting . Quiver s can be mounted to hold ammunition . These are often made from plastic and usually hold the bolts in fixed positions along the structure . A popular detachable design consists of a main arm that is attached to the weapon , a plate on one end that secures four or more individual bolts at a point on their shafts and at the other end a cover that secures their heads . This kind of quiver is attached under the front of the crossbow , parallel to the string and is designed to be quickly detached and reattached . Other designs hold bolts underneath the crossbow parallel to the stock , sometimes on either side of the crossbow . A major cause of the sound of shooting a crossbow is vibration of various components . Crossbow silencers are multiple components placed on high vibration parts , such as the string and limbs , to dampen vibration and suppress the sound of loosing the bolt . History . East Asia . According to Sir Joseph Needham in his Science and Civilisation in China , though there is no way of answering the question of whether the crossbow first arose among the cultures neighboring ancient China before the rise of Chinese culture in their midst , or whether it spread outwards from China to all the environing peoples ; the former seems the more probable hypothesis given linguistic evidence , which posits that the Chinese word for ' crossbow ' came from an Austroasiatic language . Bronze crossbow bolts dating as early as the mid - 5th century BC were found at a State of Chu burial site in Yutaishan , Hubei . The earliest handheld crossbow stocks with bronze trigger , dating from the 6th century BC , comes from Tomb 3 and 12 found at Qufu , Shandong , capital of the State of Lu . Other early finds of crossbows were discovered in Tomb 138 at Saobatang , Hunan dated to the mid - 4th century BC . Repeating crossbow s , first mentioned in the " Records of the Three Kingdoms " , were discovered in 1986 in Tomb 47 at Qinjiazui , Hubei dated to around the 4th century BC . The earliest Chinese document mentioning a crossbow is in scripts from the 4th to 3rd centuries BC attributed to the followers of Mozi . This source refers to the use of a giant crossbow in the 6th to 5th centuries BC , corresponding to the late Spring and Autumn Period . Sun Tzu ' s influential book " The Art of War " ( first appearance dated in between 500 BC to 300 BC ) refers in chapter V to the traits and in XII to the use of crossbows . One of the earliest reliable records of this weapon in warfare is from an ambush , the Battle of Ma - Ling in 341 BC . By the 200s BC , the crossbow ( ) was well developed and quite widely used in China . The earliest textual evidence of the " handheld " crossbow used in battle dates to the 4th century BC . Handheld crossbows with complex bronze trigger mechanisms have also been found with the Terracotta Army in the tomb of Qin Shihuang ( r . 221 – 210 BC ) that are similar to specimens from the subsequent Han Dynasty ( 202 BC – 220 AD ) , while crossbowmen described in the Qin and Han Dynasty learned drill formations , some were even mounted as cavalry units , and Han Dynasty writers attributed the success of numerous battles against the Xiongnu to massed crossbow fire . The bronze triggers were designed in such a way that they were able to store a large amount of energy within the bow when drawn , but was easily fired with little recoil when the trigger were pulled ( this allowed it for precision shooting ) . The metal portions of the crossbow were also mass - produced with precision , with the bronzer mechanisms being interchangeable . Finally , the Qin and Han Dynasties also developed crossbow firing lines , with alternating rows of crossbowmen firing and reloading similar to a musket firing line . In Vietnamse historical legend , the ruler and general Thục Phán who ruled over the ancient kingdom of Âu Lạc from 257 to 207 BC is said to have owed his power to a magic crossbow , capable of shooting thousands of arrows at once . Different varieties of crossbows were also developed , such as the repeating crossbow , multi - shot crossbow , and repeating multi - shot crossbow . Ancient Greece . The earliest reasonably reliable date for the crossbow in the Greek world is from the 5th century BC . The historian Diodorus Siculus ( fl . 1st century BC ) , described the invention of a mechanical arrow firing catapult ( " katapeltikon " ) by a Greek task force in 399 BC . According to the inventor Hero of Alexandria ( fl . 1st century AD ) , who referred to the now lost works of the 3rd - century BC engineer Ctesibius , this weapon was inspired by an earlier hand crossbow , called the " gastraphetes " ( " belly shooter " ) , which could store more energy than the Greek bows . A detailed description of the " gastraphetes " , along with a drawing , is found in Heron ' s technical treatise " Belopoeica " . The " gastraphetes " was powered by a composite bow . It was cocked by resting the stomach in a concavity at the rear of the stock and pressing down with all strength . In this way considerably more energy can be summoned up than by using only one arm of the archer as in the hand - bow . The heavy weight and bulk of the " gastraphetes " may have necessitated a prop to keep it standing , i . e . by mounting it on a defensive wall or using a portable prop . A third Greek author , Biton ( fl . 2nd century BC ) , whose reliability has been positively reevaluated by recent scholarship , described two advanced forms of the " gastraphetes " , which he credits to Zopyros , an engineer from southern Italy . Zopyrus has been plausibly equated with a Pythagorean of that name who seems to have flourished in the late 5th century BC . He probably designed his bow - machines on the occasion of the sieges of Cumae and Milet between 421 BC and 401 BC . The bows of these machines already featured a winched pull back system and could apparently throw two missiles at once . From the mid - 4th century BC onwards , evidence of the Greek use of crossbows becomes more dense and varied : Arrow firing machines ( " katapeltai " ) are briefly mentioned by Aeneas Tacticus in his treatise on siegecraft written around 350 BC . An Athenian inventory from 330 – 329 BC includes catapults bolts with heads and flights . Arrow firing machines in action are reported from Philip II ' s siege of Perinthos in Thrace in 340 BC . At the same time , Greek fortifications began to feature high towers with shuttered windows in the top , presumably to house anti - personnel arrow shooters , as in Aigosthena . The transition to the torsion catapult s , which are not considered crossbows and came to dominate Greek and Roman artillery design is first evident in inventories of the Athenian arsenal from between 338 and 326 BC . Torsion weapon s , which rely on the energy generated from twisted animal sinew became siege weapons and light artillery – such as the Greek ballista or the Roman scorpion . In Roman times the crossbow became to be known as arcuballista . Roman Empire . Besides the " gastraphetes " , the ancient world knew a variety of mechanical hand - held weapons similar to the later medieval crossbow . The exact terminology is a subject of continuing scholarly debate . Greek and Roman authors like Vegetius ( fl . 4th century ) note repeatedly the use of arrow firing weapons such as " arcuballista " and " manuballista " respectively " cheiroballistra " . While most scholars agree that one or more of these terms refer to handheld mechanical weapons , there exist disagreement whether these were flexion bows or torsion powered like the recent Xanten find . The Roman commander Arrian ( c . 86 – after 146 ) records in his " Tactica " Roman cavalry training for firing some mechanical handheld weapon from horseback . Sculptural reliefs from Roman Gaul depict the use of crossbows in hunting scenes . The specimen are remarkably similar to the later medieval crossbow , including the typical nut lock ( see image ) . Medieval Europe . The crossbow is portrayed as a hunting weapon on four Pictish stones from early medieval Scotland ( 6th to 9th centuries ) : St . Vigeans no . 1 , Glenferness , Shandwick , and Meigle . The use of crossbows in European warfare is again evident from the Battle of Hastings until about the year 1500 . They almost completely superseded hand bows in many European armies in the 12th century for a number of reasons . Although a longbow achieves comparable accuracy and faster shooting rate than an average crossbow , crossbows release more kinetic energy and can be used effectively after a week of training , while a comparable single - shot skill with a longbow takes years of strength training to overcome the draw strength of the longbow , as well as years of practice needed to use it with skill . In the armies of Europe , mounted and unmounted crossbowmen , often mixed with javeliners and archers , occupied a central position in battle formations . Usually they engaged the enemy in offensive skirmishes before an assault of mounted knight s . Crossbowmen were also valuable in counterattacks to protect their infantry . The rank of commanding officer of the crossbowmen corps was one of the highest positions in any army of this time . Along with polearm weapons made from farming equipment , the crossbow was also a weapon of choice for insurgent peasants such as the Taborite s . Mounted knights armed with lances proved ineffective against formations of pike men combined with crossbowmen whose weapons could penetrate most knights ' armor . The invention of pushlever and ratchet drawing mechanisms enabled the use of crossbows on horseback , leading to the development of new cavalry tactics . Knights and mercenaries deployed in triangular formations , with the most heavily armored knights at the front . Some of these riders would carry small , powerful all - metal crossbows of their own . Crossbows were eventually replaced in warfare by more powerful gunpowder weapons , although early guns had slower rates of fire and much worse accuracy than contemporary crossbows . Later , similar competing tactics would feature harquebusiers or musket eers in formation with pikemen ( pike and shot ) , pitted against cavalry firing pistol s or carbine s . Elsewhere . The Saracens called the crossbow " qaws Ferengi " , or " Frankish bow , " as the Crusaders used the crossbow against the Arab and Turkoman horsemen with remarkable success . The adapted crossbow was used by the Islamic armies in defence of their castles . Later footstrapped version become very popular among the Muslim armies in Iberia . During the Crusades , Europeans were exposed to Saracen composite bow s , made from layers of different material — often wood , horn and sinew — glued together and bound with animal tendon . These composite bows could be much more powerful than wooden bows , and were adopted for crossbow prods across Europe . In Western Africa and Central Africa , crossbows served as a scouting weapon and for hunting , with the Spanish and the Portuguese bringing the technology to America . In the American south , the crossbow was used for hunting when firearms or gunpowder were unavailable because of economic hardships or isolation . In Northern America , light hunting crossbows were traditionally used by the Inuit . The native Montagnard s of Vietnam ' s Central Highlands were also known to have used crossbows , as both a tool for hunting , and later , an effective weapon against the Viet Cong during the Vietnam War . Montagnard fighters armed with crossbows proved a highly valuable asset to the US Special Forces operating in Vietnam , and it was not uncommon for the Green Berets to integrate Montagnard crossbowmen into their strike teams . Modern use . Hunting , leisure and science . Crossbows are used for shooting sport s and bowhunting in modern archery and for blubber biopsy samples in scientific research . Crossbows are the signature weapons of " The Walking Dead " ' s fictional TV series characters Daryl Dixon ( who uses a Horton Scout HD 12 crossbow , which Reedus says he takes home after filming ) and Shumpert . Modern military and paramilitary use . Up to World War II , the US Office of Strategic Services used the Big Joe 5 crossbow for assassinations . In modern times crossbows are no longer used for this , but there are still some applications . For example , in the Americas , the Peruvian army ( Ejército ) equips some soldiers with crossbows and rope , to establish a zip - line in difficult terrain . In Brazil the CIGS ( Jungle Warfare Training Center ) also trains soldiers in the use of crossbows . In the United States , SAA International Ltd manufacture a 150 ft · lb crossbow - launched version of the U . S . Army type classified Launched Grapnel Hook ( LGH ) , among other mine countermeasure solutions designed for the middle - eastern theatre . It has been successfully evaluated in Cambodia and Bosnia . It is used to probe for and detonate tripwire initiated mines and booby traps at up to 50 meters . The concept is similar to the LGH device originally only fired from a rifle , as a plastic retrieval line is attached . Reusable up to 20 times , the line can be reeled back in without exposing oneself . The device is of particular use in tactical situations where noise discipline is important . In Europe , British - based Barnett International supplied crossbows to Serbian forces which according to " The Guardian " were later used " in ambushes and as a counter - sniper weapon " , against the Kosovo Liberation Army during the Kosovo War in the areas of Pec and Djakovica , south west of Kosovo . Whitehall launched an investigation , though the department of trade and industry established that not being " on the military list " crossbows were not covered by such export regulations . Paul Beaver of Jane ' s defence publications commented that , " They are not only a silent killer , they also have a psychological effect " . On 15 February 2008 Serbian Minister of Defence Dragan Sutanovac was pictured testing a Barnett crossbow during a public exercise of the Serbian army ' s Special Forces in Nis , 200 km south of capital Belgrade . Special forces in both Greece and Turkey also continue to employ the crossbow . Spain ' s Green Berets still use the crossbow as well . In Asia , Chinese armed forces use crossbows at all unit levels from traffic police to the special force Snow Leopard Commando Unit of the People ' s Armed Police and the People ' s Liberation Army . One justification for this comes in the crossbow ' s ability to stop persons carrying explosives without risk of causing detonation . Furthermore , during the Xinjiang riots of July 2009 , crossbows were used alongside modern military hardware to quell protestors . The Indian Navy ' s Marine Commando Force were equipped until the late 1980s with crossbows supplied with cyanide - tipped bolts , as an alternative to suppressed handgun s . Comparison to conventional bows . With a crossbow , archers could release a draw force far in excess of what they could have handled with a bow . Furthermore the crossbow could hold the tension for a long time , whereas even the strongest longbowman could only hold a drawn bow for so long . The disadvantage is the greater weight and clumsiness compared to a bow , as well as the slower rate of fire and the lower efficiency of the acceleration system , but there would be reduced elastic hysteresis , making the crossbow a more accurate weapon . Crossbows have a much smaller draw length than bows . This means that for the same energy to be imparted to the arrow ( or bolt ) , the crossbow has to have a much higher draw weight . A direct comparison between a fast hand - drawn replica crossbow and a longbow show a 6 : 10 rate of fire or a 4 : 9 rate within 30 seconds and comparable weapons . Legal issues . Can . 29 of the Second Lateran Council under Pope Innocent II in 1139 banned the use of crossbows , as well as slings and bows , against Christians . Today , the crossbow often has a complicated legal status due to the possibility of lethal use and its similarities to both firearms and archery weapons . While some jurisdictions regard crossbows the same as firearms , many others do not require any sort of license to own a crossbow — even for people , such as felons , who may not legally possess a firearm . The legality of using a crossbow for hunting varies widely around the world , and even within different jurisdictions of some federal countries .