Everyone has standards on how to write a chapter, and I believe that there are people who treat said personal standards as strict guidelines of what a chapter should contain. And because I have insecurities, and need to constantly compare myself with the writing style of others, I have to ask: Dear Reader, what are your writing standards? As for me, I'll list my own down:
1) A chapter should be a complete idea. 2) A chapter should be long enough to express that idea; while there is no hard limit, a minimum of about 400-500 words is to be expected. 3) A chapter should end with a reasonable question that prompts at least two alternatives. 4) Batshit insane or weird ideas should be pursued with all the care and consideration of perfectly rational and normal ideas, if not more. 5) Chapter titles should be descriptive of the contents.
1) A chapter should tell it's own small story and end with a meaningful decision (even if it's a linear story). 2) Grammar, spelling, and punctuation should be perfect. 3) CONSISTENCY is absolutely essential. If a person's name is Kathy one chapter it can't magically change to Cathy. 4) The reader should be able to place yourself in the shoes of the POV character and visualize what they're seeing.
I do have standards but they're not anything strictly defined. The only things I keep as standards for sure are: 1. I do at least one editing pass, having learned my lesson that I'll always miss or be able to improve on something, in terms of grammar or flavor. 2. The end of the chapter should be either a question, a choice, or a logical stopping point. 3. I will hesitate to post a chapter that doesn't have at least something spicy or entertaining or thought-provoking to enjoy; that's mostly just a reminder to myself not to release something bone dry in the service of getting from point A to point B, because I'd never read that sort of chapter myself. 4. I have no strict standards on min/max length, but in terms of minimum, I like the way Zeebop proposed it: an idea, and enough length to express that idea. These aren't standards for me in the sense of "If I do this, I'll always have great writing!" They're standards in the sense of "If I didn't do these, it'd feel totally wrong."
A chapter can take on many forms. In a linear story, it doesn't need to end in a potential decision. In a game mode story, it doesn't need to align with a minimum or maximum length, nor would that be feasible to track. It doesn't need to finish expressing a single idea if doing so would make it unwieldy, nor is it limited to just one idea. Each story has its own needs, and I can't really think of anything about the concept of chapters in particular that demands any inherent restrictions. As an author, I'm willing to structure my chapters in whatever way makes sense for my story. I have standards for writing, worldbuilding and storytelling, but none that specifically apply to chapters as a medium.
