👉 The hired fluid, also known as the "fluid of hire" or "mercenary fluid," is a historical term referring to a specialized liquid used in ancient warfare, particularly by mercenary groups. This fluid was typically a mixture of oil, water, and sometimes other substances like vinegar or animal fat, applied to the skin or hair of soldiers to create a slippery effect, making them easier to maneuver and fight with. The hired fluid was often used by mercenaries due to its relatively low cost compared to other methods of enhancing agility, such as armor or specialized training. While its effectiveness varied, the hired fluid played a significant role in the tactics of ancient armies, especially those composed of mercenaries.