1. Arrive at your seat and drape your super-puffy down coat over the back of your chair so that the hood, collar and most of the rest of the garment rests in the lap of the person behind you.
2. Do not remove your hat. The patron behind you has no right to an unobstructed view.
3. Wear lots of jangling jewelry and remember to pile your hair atop your head in such a way as to create your own personal tribute to the Washington Monument. Also, wear your stinkiest perfume or after-shave, the one you save for occasions during which the largest possible circle of unsuspecting people can gag on it.
4. Leave your smartphone on, and turn up the volume to full. Optimally, you should have it in your lap, with the LED display creating a blue halo that competes with the production's touching, climactic scene. If your choice is to leave the phone on in your pocket or handbag, make sure it's so difficult to fumble for that four full rings occur before you can finally turn it off. Better yet, let it just continue to ring.
5. When you sneeze or cough, do not cover your mouth. If your seat mates are anti-vaxxers, that's on them.
6. If you have brought hard candy, don't merely unwrap it very, very, very slowly, in the belief that prolonging the exercise muffles the effect. Also, mindlessly play with the wrapper afterward, so that the crinkling sound lasts all the way through the second act.
7. If the production is an old musical you know and love, just sing along. Everyone would rather hear you than the Juilliard-trained leading lady. And if you don't know the words, humming is absolutely fine.
8. Couples who can't live a waking moment without snuggling should feel free to be all over each other, regularly shifting the angles at which their heads nestle into the other's shoulder. The head-swaying chain reaction in the rows behind you provides a bonus form of neck exercise from which playgoers of all ages will benefit.
9. Loudly ask as many questions as you want to about the plot twist you missed because you were daydreaming, or about the line you didn't understand because the actor is putting on a French accent. Ignore the crabby patron who keeps turning to shoot you dirty looks. You have rights, too: There are laws in place to protect the bewildered.
10. And please, at all times, behave in a public auditorium as though you were on the sofa at home, watching Netflix. The armrests on both sides of your seat have been put there for your exclusive use. Who else's elbows could possibly be half as important?