In battles you will often see arrows that are on fire (especially at night). These arrows are used to set enemies on fire. This can also happen to ballista arrows, catapult rocks, and various other projectiles. Even if there is no sane reason for them to be on fire. Fire is just cool. Though arrows can still get even cooler, especially if shot en masse in a Rain of Arrows. Lighted arrows in real life were used to Molotov Cocktails are arguably the modern counterpart. Examples of Arrows on Fire include: