Attrition Warfare is a military tactic where one side attempts to gain victory in battle or in a war as a whole by wearing down the opposing side to the point of collapse through continuous losses in men, equipment, and resources.
Such a battle or war will generally be won with the side with the greater amount of men, equipment, and resources.
 History in Total War
Attrition warfare is common in a scenario where both players have a similiar amount of melee and ranged troops, and neither side is e=inferior nor superior to the other. If both commanders undertake a similiar strategy, then such a battle or war will usually be a long and drawn-out one where both sides suffer heavy losses and the result is a close victory.
Attrition-based battles in the melee-based Total War games were common in Rome: Total War during conventional Rome vs. Rome battles.
Missile wars and skirmish warfare are both forms of intended attrition warfare, while a melee slugout is an unintended form of attrition warfare. Naval battles can also decided through attrition warfare.
 Attrition-based Armies
Armies specifically chosen to conduct attrition warfare in Total War can be chosen, and they are common at higher funds, usually at 20,000 and above. Such armies normally consist of many fully-upgraded defense-oriented heavy units, such as Urban Cohorts or Papal Guard.
Skirmish armies or missile-heavy armies can also be considered attrition-based armies. These armies may consist of 8 long-ranged units or more, and are specifically made to wear out the opposing army. Missile-heavy armies, however, may be countered through a Rush.
Because this level of funds cannot be normally reached in Empire: Total War or Napoleon: Total War, attrition armies are not very common; those that exist are militia-heavy in order to exhaust enemy ammunition and provide for cannon fodder.