Are you wearing a long sleeve shirt? Idiot. Tear the sleeves off immediately. Are you a woman? Insure that at least your knees are showing, but preferably mix in some thigh, as well. Décolletage should be displayed prominently.
First commercial break
Invent an impossibly elaborate lie, which you will add to as the game goes on. If details of the lie contradict each other, press on without acknowledging it.
Mack is shown clapping on camera
Call a random BYU student and actively discourage their commitment to the honor code.
Swear at the television. Bonus points for creative combinations like "fucksatchel" and "taint-sniffing shitgoblin".
Texas scores first
Excuse yourself from weekly religious services.
Meticulously catalog a collection of exotic pornography, cross-indexing by genre, sub-genre, age ranges, performers and dimensions of performers' assets.
Daje Johnson touches the football
Take a tug off an energy drink.
Daje Johnson scores
Pound the remaining energy drink, shake your bare genitals at the person nearest you.
Be openly disrespectful to someone you've never met, especially that asshole right over there.
Texas leads at halftime
If you're unmarried, find someone to have carnal relations with. If married, engage in relations, but make sure that it's not for the purpose of procreation. Consider sinning it up a bit by recording tasteful footage on your phone, or mixing in some sodomy. Maybe both! Let the scoreboard be your guide here.
Texas tied or trailing at halftime
Begin growing a beard immediately, irrespective of gender or follicular prowess.
Enjoy a mixed beverage containing both alcohol and caffeine. Jack and Coke is a solid option, though schnapps and Crystal Lite with a Red Bull chaser is acceptable if you're Sailor Ripley.
Texas turns the ball over 3 times
Score an eight-ball off your sketchy neighbor or cousin, begin doing lines. Stop when Texas regains possession.
An asinine, obviously incorrect call is upheld on review
Jaywalk in plain site of a law enforcement official.
BYU turns the ball over
Invite someone of the opposite sex back your place after curfew. Wink. Nod knowingly.
BYU takes the lead
Brandish a firearm.
BYU takes a two-score lead
Discharge your firearm into the television, or an area near enough to the television to indicate your disapproval.
Three Texas running backs in on the same play
Smoke an entire pack of Marlboro Reds, either simultaneously or in sequence.
Shotgun a quart of espresso. Optionally, stir in some greenies with a meth-coated swizzle stick.
Pick three from the list above.
Complete the entire list, in order.
Good luck out there, gang, and be sure to chronicle the results for posterity. Hook 'em.