Genre conventions are the "rules" that define genres. Since every genre is different, each genre comes with its own conventions. Those conventions differentiate the types of genres, and your ability to use those conventions will affect how audiences perceive your work.
Conventions are social constructs. Groups and cultures decide what a genre looks like.
Some conventions are very basic. If you pick up a book, you expect it to be a stack of pages with words. Toss in a DVD with a movie, and you assume it's going to include video and background music.
Specific genres will have more complex rules. In novels and movies, there's a big difference between a romance and a horror — one should be filled with love and social drama, whereas the other should build tension through fear. You don't watch romcoms for the jump scares.
Genre conventions are constantly changing. Once upon a time, movies had no sound — since there was no way to include a soundtrack on early film, piano players sat in the corner playing sheet music while the film reel spun (George Eastman Museum). Nowadays, technology and special effects allow so many layers of audio that it can be difficult to make out the dialogue in modern movies (Kernan).
Conventions are affected by the materials available, but commonalities persist. If you have a Kindle, you might be able to hold eight hundred books in the palm of your hand — no physical paper needed. Because of this, it's now much, much cheaper to distribute books — self-published authors are posting fan fiction novels that never would've been picked up by a traditional publisher. And with streaming video services, you don't need a DVD or a film reel or a VCR — and there are thousands of YouTubers and TikTokers putting together their own channels of video content. But you still expect a self-published fan fiction novel to have a large number of words expressing plot and characterization like the literary novels you were assigned in school, and even the shortest Facebook reels likely include background music to go with the video.
When we're talking conventions, the "rules" of communication fall into a few major categories. For each category, audiences expect your genre to meet their expectations. That doesn't always mean you follow the genre exactly — often, the most effective forms of communication are memorable because they break our expectations. But if you want that broken expectation to work, it helps to know what people expected in the first place:
Modality: Is your genre visual? Audible? Printed on a page? Shouted from a soapbox? Expressed through a simple smile? This is really important, especially for academic genres. For example, I'm often asked if documentaries count as scholarly sources, and the answer is always no. If it's a video, it's not a scholarly source — scholarly sources are always several pages of text with a lot of citations and possibly some charts and images. It doesn't matter if a doctor on YouTube has published a number of scholarly articles in The Lancet — their video announcing those findings is not a peer-reviewed source. On the other hand, some genres might not be written down at all. Consider the "Stringer Bell Rule" from The Wire: one should probably avoid "taking notes on a criminal f***ing conspiracy" (Gaughan).
Language and Diction: So many genres depend on language. You might need a selection of specific words, or they might need to be written or spoken or even sung. We often judge others based their word choice — and this is especially true for genres. We expect scholarly sources to have some long and difficult terminology — but confusing scholarly words don't go viral on TikTok. The most memorable songs and poems often include words that rhyme — but you'd get really weirded out if your friend came up to you and started rhyming every other sentence they spoke.
Length: How much time will your audience spend on this genre? Toddlers have a much shorter attention span than teenagers, so a picture book is only a few pages with a limited number of words while that novel your teacher assigned goes on forever and ever and ever. Or so it seems. Resumes need to be single page because most employers review applications quickly, but a curriculum vitae for an academic position might run six or more pages in order to capture every single article that scholar has ever published. Tweets are limited to a set number of characters. Your favorite hit song is probably three to five musicians performing for only a few minutes, whereas classical symphonies generally require a full orchestra performing for around half an hour (Scully).
Let's consider the example of resumes. As a genre, the resume has some very strict conventions. Most resumes are only a single page long. Employers expect your resume to include a list of your educational achievement, prior work experience, and a way to contact you. If your resume is too long or too short, or if it's missing critical information, it's unlikely you'll be hired for the job you want.
Within those conventions, there's still room for variation. For example, printed and electronic resumes have important differences. Paper resumes are supposed to be printed on high-quality paper — and you can still purchase this cotton fiber "resume paper" at your office supply store. But electronic versions? No paper needed. You don't even need access to a printer. But there's a catch: electronic resumes sent to large corporations are likely to be scanned by electronic applicant tracking systems (ATS) before they reach human eyes. So you may need to include specific keywords from the job posting — and some resume writers have resorted to "keyword packing" at the bottom of their resumes in order to trick these systems into approving a resume that's otherwise pretty bland. But does that actually work? Based on a Reddit discussion for "optimizing" resume keywords, people disagree about how to use resume keywords to get hired. CreditOk5063 claims that "88% of employers believe they are losing out on high-qualified candidates because their resume [sic] . . . do not include keywords." But according to HeadlessHeadhunter, an ATS sorts candidates "based on the order they apply," so worrying about keywords can actually hurt your hiring chances if you waste time before submitting.
So you need to be careful with your conventions. When you write, you need to consider the situation:
Which audience are you writing for? Resumes are generally written for a potential employer who's short on time, so successful resumes tend to be short and professional.
What conventions does your audience expect? An employer wants a summary of your past employment — not a letter of complaint. You won't get hired if you turn in eighteen pages of grease-stained notebook paper explaining why your old boss was a jerk. In fact, that kind of "resume" won't even get read — if you're lucky, it'll go straight to the trash before it destroys your reputation.
How are these conventions determined? Who decides what they are? Resumes have a long history, and the modern version became a "standard" in the 1950s (Davron). Despite the advent of computers, email, and online job postings, employers still find the short, single-page summary of an applicant's job qualifications to be helpful. And if you want to get hired by a specific employer, you need to know how that company uses the genre. If you mail in a paper copy, will it get tossed in the wastebasket because the hiring team only reviews digital applications? Is this a big company that uses an automated system to rate thousands of applicants, or are you only one of five applicants to a small family-owned company? It makes a difference.