But whether they actually understand the code is another question. For those unfamiliar with skiing and snowboarding, it’s likely something they’ve never heard of.

That’s all changing as actor Gwyneth Paltrow’s highly publicized ski collision trial is live-streamed from the courtroom. The actor-turned-lifestyle-influencer was accused of crashing into a fellow skier during a 2016 family trip to the upscale, skiers-only Deer Valley Resort in Utah. The celebrity trial is on day six and expected to conclude Thursday.

For a week, the trial has shone a spotlight on the unspoken rules that govern behavior on the slopes. Testimony has repeatedly touched on skier’s etiquette — especially sharing contact information after a collision, and ski turn radiuses — in the most high-profile ski collision trial in recent history.

There are about 100 code-related lawsuits playing out now outside the spotlight, but most cases are settled before going to trial.

Throughout Paltrow’s trial, the word “uphill” has emerged as synonymous with “guilty,” as attorneys have focused on one of the code’s main tenets: The skier who is downhill or ahead on a slope has the right of way. “You must avoid them,” the code instructs uphill skiers.

Rather than focus solely on the question of who hit who, attorneys for both sides have questioned nearly every witness — from Paltrow’s private ski instructors to doctors for the man suing Paltrow — about who was downhill at the time of the collision.

After initially suing Paltrow for $3.1 million, retired optometrist Terry Sanderson is now suing for at least $300,000 in damages. Paltrow has countersued for $1 and attorney fees, claiming Sanderson ran into her.

The question has become a focal point of the trial, as both sides call legions of family members, friends and doctors to testify in Park City — the posh Rocky Mountain resort town that draws a throng of celebrities each year for the Sundance Film Festival.

In the courtroom, attorneys have used the term “downhill” hundreds of times each day to try to persuade the jury that the opposing side represents the skier who was uphill and to blame.

Paltrow’s legal team has invested heavily in convincing the jury that she was downhill when the crash happened, even commissioning artists to render their client’s version of events with multiple, advanced animations.

Because no video footage of the collision was included as evidence, the recollections of a ski buddy of Sanderson’s who claimed last week to be the collision’s sole eyewitness has become a sticking point for Paltrow’s team.

Over objections from Sanderson’s attorneys, the court has allowed Paltrow’s team to play three of the seven high-resolution animations on a projector positioned between witnesses and the jury box — showing the eyeball-like prunes of Deer Valley’s aspen trees, the ski coats of Paltrow’s children and groomed snow on Bandana, the beginner run where Sanderson and Paltrow crashed.

Irving Scher, a biomechanical engineer hired by Paltrow’s defense team, used a dry-erase marker to draw stick figures and line graphs, and to jot down equations for force and torque to argue that science supported Paltrow’s claim that she was downhill when the collision began.

“Ms. Paltrow’s version of events is consistent with the laws of physics and how people move and rotate,” Scher testified Tuesday.

In an equally theatrical display last week, Sanderson’s lawyers tried to rope Paltrow into a reenactment of events to poke holes in her claim that Sanderson ran into her from behind — yet ended up on top when the two plummeted to the ground. Her attorneys objected to the actor’s participation in the reenactment and the judge put the kibosh on that.

While there are minor differences in state laws when it comes down to finding fault, “in court it becomes a question of who was the uphill skier,” said Denver attorney Jim Chalat, who has litigated cases in Utah as well. His firm, Chalat Hatten & Banker, has 20 active collision cases in Colorado alone.

“It’s the uphill skier who is almost always in a position to cause the crash,” Chalat said Monday. “If you’re skiing too fast for your own ability and you can’t carve out a turn, and you hit someone, you’re going to be in trouble.”

Still, crashes between skiers are rare. The majority of incidents resulting in injuries or death occur when skiers or snowboarders slam into stationary objects, usually trees. Collisions involving people represent only about 5% of skier injuries, Chalat said.

During the 2021-2022 season, there were two reported fatalities as a result of collisions between two skiers, according to the National Ski Areas Association, who developed the first Skier Responsibility Code in 1962.

Experts at the Paltrow trial have called the code “rules of the road” and argued it’s ubiquitous, with similar etiquette in Canada, Australia and parts of Europe.

Even though serious crashes are uncommon, the snow sports industry has prioritized collision awareness in its safety programming. The responsibility code was recently updated to urge skiers involved in a collision to share contact information with each other and a ski area employee.

Last week, Paltrow was grilled by Sanderson’s attorneys for leaving the collision without first exchanging information with Sanderson. She said she made sure one of the family’s ski instructors handled that for her.

The majority of ski collision cases are typically settled before going to trial, and very often the payouts are covered by one’s homeowners insurance, said Los Angeles attorney John Morgan of the firm Morgan & Morgan.

Very few cases target the ski resorts where crashes occurred because of the inherent dangers that come with skiing and snowboarding, Morgan said. The mountain where the Paltrow-Sanderson collision happened, Deer Valley, was removed from the lawsuit in part because skiers absolve resorts of responsibility by agreeing to a set of rules on the back of every lift ticket.

“It’s like going to a baseball game and you get hit in the head by a foul ball. You know by sitting there that there’s some risk of that happening,” he said.