Obsidian Arrows is a technology in Age of Empires II: The Forgotten that is unique to the Mayans and researched at the Castle. It grants Archers and their upgrades a attack bonus against standard buildings.
Archer armies are usually completely dependent on siege units to deal any damage to buildings, since their overall damage is lower than melee units and buildings naturally have armor. The Mayans are particularly dependent on archers, having a limited tech tree for other unit types and no access to cavalry.
With the addition of Obsidian Arrows, a large group of Mayan Archers actually becomes a severe threat to buildings, since all units in the group can be damaging the same building at the same time without having to surround it, letting them pile on the damage quicker and from a safe distance. For example, Castle Age Crossbowmen with Bodkin Arrow can outrange most civilizations' Town Center, and a group of 20 or so can take one down in a reasonable amount of time. This makes them an extraordinary raiding party if paired with units to handle their counters, such as Pikemen for cavalry or Eagle Warriors for Skirmishers.
Blacksmith upgrades should still be prioritized since they add the same damage against everything plus range while being overall cheaper, and Plumed Archers do not benefit from Obsidian Arrows. When playing in team games and if the Mayan player has a Saracen ally, it also adds the team bonus of +2 attack bonus against buildings for Archers for a total of +8.
- Obsidian Arrows gives Archers +4 attack against buildings.
The African Kingdoms
- Obsidian Arrows now gives Archers +6 attack against buildings. With patch 4.8, Archers also gain +6 attack against stone defenses.
- With update 42848, Obsidian Arrows no longer grants double the attack bonus versus Stone Walls, Stone Gates, Towers, and Harbors.
Lords of the West
- With update 44725, Obsidian Arrows has been removed and replaced by the Hul'che Javelineers technology.
- At launch, the additional +6 (+4 in The Forgotten) attack against stone defenses did not trigger due to a bug. However, this was fixed with patch 4.8.
- In real life, obsidian arrows are extraordinarily sharp, but also very brittle and often aren't re-usable. Despite their sharpness, they are not well suited to destroying masonry or walls, and are in fact easily defeated by as little as a wooden board.
- Competitive players thought that having large foot archer bonuses against buildings was not healthy for the game, as archers are supposed to be stopped by buildings, which lead to the removal of Obsidian Arrows and the new Saracen bonus at release of the Definitive Edition.
- A lot of players regard the removal of this technology as a great nerf for Mayans, since it gives a large bonus for their archers. Conversely, the Mayans are now have a better win–rate with their new technology than before.