I love commas. Between them and the semicolon, my writing is populated (some say overpopulated) with pauses, breaks, and spaces to breathe, sharing with the reader the pace and clarity I hope for. Commas have more jobs than any other punctuation mark, which is why so many writers treat them like seasoning and sprinkle them wherever a sentence feels bland. In The Language of Fiction, Brian Shawver argues that real rules lie beneath it all. He focuses on four that give fiction writers the most trouble, plus a few common mistakes. 1. Two complete thoughts get a comma before the "and." "I went to the game, and I bought a hot dog" has two independent clauses, so the comma goes in. "I went to the game and bought a hot dog" has one subject doing two things, so it doesn't. Shawver almost lost a teaching job over this one. Writers bend it all the time, though. Drop the commas from a chain of clauses and the prose rushes forward, which is useful in a chase or a panic. Just watch for misreads. In "Jerry whacked the baseball and his father grinned," readers spend a half-second picturing Jerry hitting his dad. 2. Commas separate items in a list. That part is simple. The Oxford comma before the final "and" has no settled standard, so pick a side and stay consistent. The craft is in the variations. Leave out the final "and," and the list ends abruptly, with the last item landing hard. Swap every comma for "and," as in "lions and tigers and bears," and the list feels crowded and overflowing. Tim O'Brien uses both in "The Things They Carried" so his many lists never fall into the same rhythm. 3. Equal adjectives get commas. Stacked ones don't. "The spastic, gray poodle" needs a comma because both words describe the poodle equally. "The fat German shepherd" doesn't need a comma because "fat" describes the whole phrase "German shepherd." To test it, put "and" between the adjectives or reverse their order. If it still sounds right, use the comma. This rule also gets broken on purpose. Hemingway's "plump brown legs" skips the comma because the words are short and quick. George Saunders writes "fat little unemployed guy" without commas because the line is meant to come out in one breath.