structural:scholar_edition, information:highlighting, linguistic:paraphrasing, information:classification
Warfare

One of the principal sources of information on Hunnic warfare is Ammianus Marcellinus, who includes an extended description of the Huns' methods of war:

They also sometimes fight when provoked, and then they enter the battle drawn up in wedge-shaped masses, while their medley of voices makes a savage noise. And as they are lightly equipped for swift motion, and unexpected in action, they purposely divide suddenly into scattered bands and attack, rushing about in disorder here and there, dealing terrific slaughter; and because of their extraordinary rapidity of movement they are never seen to attack a rampart or pillage an enemy's camp. And on this account you would not hesitate to call them the most terrible of all warriors, because they fight from a distance with missiles having sharp bone, instead of their usual points, joined to the shafts with wonderful skill; then they gallop over the intervening spaces and fight hand to hand with swords, regardless of their own lives; and while the enemy are guarding against wounds from the sabre-thrusts, they throw strips of cloth plaited into nooses over their opponents and so entangle them that they fetter their limbs and take from them the power of riding or walking.

Based on Ammianus' description, Maenchen-Helfen argues that the Huns' tactics did not differ markedly from those used by other nomadic horse archers. He argues that the "wedge-shaped masses" (cunei) mentioned by Ammianus were likely divisions organized by tribal clans and families, whose leaders may have been called a cur. This title would then have been inherited as it was passed down the clan. Like Ammianus, the sixth-century writer Zosimus also emphasizes the Huns' almost exclusive use of horse archers and their extreme swiftness and mobility. These qualities differed from other nomadic warriors in Europe at this time: the Sarmatians, for instance, relied on heavily armored cataphracts armed with lances. The Huns' use of terrible war cries are also found in other sources. However, a number of Ammianus's claims have been challenged by modern scholars. In particular, while Ammianus claims that the Huns knew no metalworking, Maenchen-Helfen argues that a people so primitive could never have been successful in war against the Romans.

Hunnic armies relied on their high mobility and "a shrewd sense of when to attack and when to withdraw". An important strategy used by the Huns was a feigned retreat—pretending to flee and then turning and attacking the disordered enemy. This is mentioned by the writers Zosimus and Agathias. They were, however, not always effective in pitched battle, suffering defeat at Toulouse in 439, barely winning at the Battle of the Utus in 447, likely losing or stalemating at the Battle of the Catalaunian Plains in 451, and losing at the Battle of Nedao (454?). Christopher Kelly argues that Attila sought to avoid "as far as possible, large-scale engagement with the Roman army". War and the threat of war were frequently-used tools to extort Rome; the Huns often relied on local traitors to avoid losses. Accounts of battles note that the Huns fortified their camps by using portable fences or creating a circle of wagons.

The Huns' nomadic lifestyle encouraged features such as excellent horsemanship, while the Huns trained for war by frequent hunting. Several scholars have suggested that the Huns had trouble maintaining their horse cavalry and nomadic lifestyle after settling on the Hungarian Plain, and that this in turn led to a marked decrease in their effectiveness as fighters.

The Huns are almost always noted as fighting alongside non-Hunnic, Germanic or Iranian subject peoples or, in earlier times, allies. As Heather notes, "the Huns' military machine increased, and increased very quickly, by incorporating ever larger numbers of the Germani of central and eastern Europe". At the Battle of the Catalaunian Plains, Attila is noted by Jordanes to have placed his subject peoples in the wings of the army, while the Huns held the center.

Peter Heather notes that the Huns were able to successfully besiege walled cities and fortresses in their campaign of 441: they were thus capable of building siege engines. Heather makes note of multiple possible routes for acquisition of this knowledge, suggesting that it could have been brought back from service under Aetius, acquired from captured Roman engineers, or developed through the need to pressure the wealthy silk road city states, and carried over into Europe.