Hul'che Javelineers is a technology in Age of Empires II: Definitive Edition - Lords of the West that is unique to the Mayans and can be researched at the Castle. Once researched, it improves Skirmishers by making them throw a second projectile.
The Hul'che Javelineers technology is a plain improvement to the Skirmisher line for the Mayans. It adds a second, rather inaccurate projectile that deals 1 damage. This projectile is unaffected by Blacksmith upgrades, Chemistry or Thumb Ring, but it does benefit from Ballistics.
In relative terms, Hul'che Javelineers does very little for Skirmishers to achieve more against archers and Spearmen. However, this technology greatly increases the average damage output against units which they would normally perform poorly against, such as the Militia line, and also against high pierce armor units like cavalry, siege weapons, buildings, and other Skirmishers. This crucial advantage, added to the modest cost of the technology, makes the Elite Skirmisher a more viable unit for Mayans in the late game, which due to the civilization's capabilities, was formerly limited to more gold-intensive units in its army composition.
The Hul'Che was the Mayan's choice for a reliable ranged weapon, little more than a long wooden shaft with a notch at the end, where an arrow sits. A Mayan javelineer can throw these darts and arrows at a high speed towards their enemies, giving them an advantage in overwhelming the enemy with volleys. Similar weapons included the Atl-Atl used by the Aztecs, however it was the Mesoamericans who adopted the use of such weapons heavily where as other powers in the Medieval World abandoned it in exchange for the bow or primitive gunpowder weapons.