The distinctive literary styles and themes of Robert E. Howard rely on a combination of many factors. In his fiction, he used devices borrowed from classical and traditional works, as well as formal rhetoric. In his poetry, he used rhythm, stress, and intonation to achieve a sense of motion. Some of his fiction has been described as prose poetry. His works can be distinguished by his use of violence and hate as positive forces in his universe, which can be seen as a part of the American Myth. In keeping with the era in which he worked, a grim and hardboiled theme pervades. The continuing cycle of civilisation and barbarism is highlighted in several works. Although he died before it was formally defined, an existentialism subtext runs through his writing. He was an aesthete and had affinity for romanticism and neo-romanticism, although in this he was out of step with his era.
Styles
Language and word use
Howard used an economy of words to sketch out scenes in his stories; his ability to do so has been attributed to his skill with, and experience of, both tall tales and poetry. Howard's stories have a sense of authenticity and a natural deft use of language due to his investment in the narrative. The trait is considered the mark of a master in oral storytelling. Some of his stories, such as "The Mirrors of Tuzun Thune", have been described as prose poems in their vigorous and rhythmic writing. Howard's tall tale background is the source of the rhythm, drive and authenticity of his work.
Howard's writing frequently uses hypermodification, where most nouns and most verbs are modified. Sometimes a single word can have multiple modifiers. For example, in the line "the saw-edged crescent blade of the Yuetshi", the noun "blade" is modified with both "crescent" and "saw-edged". Howard would use both compound modification (i.e. A and B) or serial modification (i.e. A, B, C). In addition to liberal use of adjectives and adverbs, he would use nominal compounds and compound verbs. Coffman writes that this is something that "in most writers, is a flaw, but which Robert E. Howard gets away with beautifully."
Howard occasionally included descriptive details as lists; the rapid succession adding to the pace of the prose. For example, "Flat, flaring nostrils, retreating chin, fangs, no forehead whatever, great, immensely long arms dangling from sloping, incredible shoulders".
His writing attempts to match the reading pace with the pace of the story, so his language is as packed as the action being depicted. In addition to the action packing of the plot (compound, modified and multi-modified verbs), descriptive passages are similarly packed with detail. Stephen King wrote that "[i]n his best work, Howard's writing seems so highly charged with energy that it nearly gives off sparks. Stories such as "The People of the Black Circle" glow with the fierce and eldritch light of his frenzied intensity."
Frequently a description is echoed or repeated, with subtle differences, throughout one of Howard's works, building a vivid descriptive resonance. For example, Xapur in the Conan story "The Devil in Iron" is variously described with the phrases "castellated", "some ancient ruins upon it", "rises sheer out of the sea", and "castle-like cliffs".
Traditional devices
Howard incorporated elements of existing narrative traditions in his writing. As well as frequent use of standard similes, he used Homeric similes, or elaborate and detailed comparisons. For example: "As a panther strikes down a bull moose at bay, so he plunged under the bludgeoning arms and drove the crescent blade to the hilt under the spot where a human's heart would be." Another element borrowed from the classical tradition is the use of epithets; the most obvious of these is "The Cimmerian" when referring to his most famous character, Conan.
He often made use of flyting, boastful and taunting dialogue preparatory to a physical fight; a device probably borrowed from Shakespeare. For example: "'Dog!' he taunted. 'You can't hit me! I was not born to die on Hyrkanian steel! Try again, pig of Turan!'" Howard's best short stories have been compared to Elizabethan plays and poems, in the sense of the strength of the narrative, the striking imagery and the sense of a larger context than man's own immediate environment. Fritz Leiber compares, "without over-praise", Howard's "The People of the Black Circle" to the plays of Christopher Marlowe and John Webster.
Rhetorical devices
Howard had a grounding in rhetorical techniques, either through self-study or formal schooling, that he used in his writing.