Dear Totally Amped…
In novels set in the ‘80s, those “old sayings” flavor the story soup—which is totally rad. Should you tack a slang glossary onto it, or onto any historical novel? I’m generally like “No way, dude” about that tack-on. I worry it would give the novel a nonfiction shading. Don’t get me wrong, nonfiction is chill and all, but your readers picked a novel. I’d rather its slang be understood from the context, or that readers pick up meaning from repeat uses (repetition rocks!), or that they just absorb the slang as the flavoring it is. That said, this is a book for young readers, and a glossary won’t tank it, so if you feel the kids might need or enjoy the boost of a glossary, go for it, dude. It’s not a wrong choice. Agents and editors won’t wig out about it during submission. Together you’ll fer sure debate the glossary’s inclusion during the book-making process and reach a team determination. If you’re self-publishing and thus making the final call yourself, I consider this a “do it if you want it” item. The goal is a bitchin’ book for readers, and smoothly incorporated ‘80s slang is righteous regardless.