Atlatl designs may include improvements such as thong loops to fit the fingers, the use of flexible shafts, stone balance weights and thinner, highly flexible darts for added power and range. Darts resemble large arrows or thin spears and are typically from 1.2 to 2.7 meters (4 to 9 feet) in length and 9 to 16 millimetre (3/8” to 5/8”) in diameter.
Another important improvement to the atlatl's design was the introduction of a small weight (between 60 and 80 grams) strapped to its midsection. Some atlatlists maintain that stone weights add mass to the shaft of the device, causing resistance to acceleration when swung, which results in a more forceful and accurate launch of the dart. Other atlatlists claim that atlatl weights add only stability to a cast which results in greater accuracy.
Based on previous work done by William S. Webb, William R. Perkins claims that atlatl weights, commonly called "Bannerstones," are artifacts characterized by a centered hole in a symmetrically shaped carved or ground stone, shaped wide and flat with a drilled hole a little like a large wing nut, are a rather ingenious improvement to the design that created a silencing effect when swung, lowering the frequency of the telltale "zip" of an atlatl in use to a more subtle "woof" sound that did not travel as far and was less likely to alert prey or other humans. Robert Berg’s theory is that the bannerstone was carried by hunters as a spindle weight to produce string from natural fibers gathered while hunting, for the purpose of tying on fletching and hafting stone or bone points.
Wooden darts were known at least since the Middle Paleolithic (Schöningen, Torralba, Clacton-on-Sea and Kalambo Falls). While the atlatl is capable of casting a dart well over 100 meters, it is most accurately used at distances of 20 meters or less. An atlatl dart is capable of killing even the largest of animals at any distance that its thrower is capable of accurately reaching since more power is applied to longer shots than shorter shots. The accuracy of the atlatl and dart tends to decrease as the distance increases. The atlatl is believed to have been in use since the Upper Paleolithic (c. 30,000 BC). Most stratified European finds come from the Magdalenian (late upper Palaeolithic). In this period, elaborate pieces, often in the form of animals, are common.
In Europe, the atlatl and dart was replaced by the bow and arrow in the Epi-Paleolithic. Along with improved ease-of-use, the bow offered the advantage that the bulk of elastic energy is stored in the throwing device, rather than the projectile; arrow shafts can therefore be much smaller, and have looser tolerances for spring constant and weight distribution than atlatl darts. This allowed for more forgiving flint knapping: dart heads designed for a particular spear thrower tend to differ in mass by only a few percent.
The atlatl has been used by early Native Americans as well. It seems to have been introduced during the immigration across the Bering Land Bridge, a wide section of exposed seabed that connected Asia and North America during the last Ice Age. The word atlatl is derived from a Nahuatl word for "water thrower," as it was most commonly used for fishing. The Aztecs reinvented the atlatl after the arrival of the Spanish conquistadores and it was used extensively during the resulting war. History shows that the Spanish feared the Aztec atlatl above all other weapons. Many unfortunate Spaniards were surprised to find the power of the weapon, which proved deadly even though it couldn't penetrate Spanish metal armor. The Inuit, tribes of the Northwest Coast, as well as south Florida native people, utilized atlatls in historical times as well. Complete wooden spearthrowers have been found on dry sites in the western USA, and in waterlogged environments in Florida and Washington.
The Shoshone of the Great Basin used this as well.
Atlatl are sometimes used in modern times for hunting. There are meetings and events where people can go atlatl in places. There is one in Rhode Island and one in Lexington held yearly. In the U.S., the Pennsylvania Game Commission has given preliminary approval for the legalization of the atlatl for hunting certain animals. Final approval would come in April 2006. The animals that would be allowed to atlatl hunters have yet to be determined, but attention is focused on deer. There are some who object, stating that the atlatl is rarely capable of a clean kill, resulting in undue suffering for the sport animal. Currently, only Alabama allows the atlatl for deer hunting, while a handful of other states list the device as legal for rough fish (those not sought for sport or food), some game birds and non-game mammals. Missouri allows use of the Atlatl for hunting wildlife except deer and turkey.