What, exactly, is a supper club? What the zócalo is to Latin Americans, the sidewalk café to Parisians, the biergarten to Bavarians, so is the supper club to Wisconsinites. It sometimes seems as if the state charter requires every Badger State community to have one. It’s the social and culinary underpinning of Wisconsin. Indeed, though supper clubs exist in many Midwestern states, Wisconsin’s density is difficult to fathom.

Equal parts homey, casual meat-and-potatoes restaurant and local kaffeeklatsch (better make that “brandyklatsch”), supper clubs traditionally have a triumvirate of obligatory specialties: prime rib, always on Saturday, although some serve it every day; homestyle chicken; and invariably a Friday-night fish fry. No fish fry, no business. Most menus feature steaks in one column, seafood in the other. Regional variations buttress these basics with anything from Teutonic carnivore fare to Turkish food. This being Wisconsin, venison occasionally makes an appearance. One side dish will always be a choice of potato. If it’s a true supper club, a relish tray comes out with the dinner rolls. On it, you’ll find everything from sliced vegetable sticks to pickles to coleslaw—and sometimes an indescribably weird “salad” concoction such as green Jell-O with shaved carrots inside.

No two supper clubs look alike (the only prerequisites are an attached bar and perhaps faux wood paneling somewhere), but all can be partially covered by clichés such as “rustic,” “cozy,” and “like someone’s dining room.” Nicer supper clubs will have crackling fireplaces; low-end joints feel more like run-down family restaurants, in both decor and menu. The coolest ones have animal heads dangling above the diners; the tackiest ones feature overdone nautical decor. Dress is completely up to you. Wear a suit and you’ll be conspicuous. Jeans are perfectly acceptable. In many places—especially Madison—Badger red is de rigueur on football Saturdays. Beware impostors: In recent years, the words “supper club” have been adopted by fancy restaurants on both coasts, but a co-opted supper club is not the real thing. If you ever see a dress code posted, you’re not at a real supper club.