NIST Laser Expert Helps Tabletop Gamers Play Safely

It's all fun and games until someone gets a laser in the eye.

Game organizer John Gianforte found this out at one of the many Warhammer 40,000 gaming tournaments he organizes in Colorado. Warhammer 40,000 is, among other things, a popular tabletop game that involves moving model warriors across a mock battlefield.

Luckily, the laser incident didn't cause any permanent harm to Gianforte. He's seen other players have close calls with lasers, which made him concerned about safety.

Gianforte explained that recent editions of the game have required more precise measurements. If you can draw a straight line between two models (game figures) on the game board, those two models can attack each other.

But it's hard to judge a measurement for "line of sight" between two small, inanimate objects. So, players use laser lines between the two models to determine whether they are eligible to attack each other.

He explained that a typical weekend tournament uses a few tables at a gaming store, while other shoppers - including children - mill around nearby. Tournaments can last up to 12 hours, which raises fatigue concerns. Given these factors, even well-intentioned players can easily make mistakes that could hurt themselves or others.

The Levels of Laser Safety

Laser pointers and other small handheld lasers may seem harmless, but they can be risky. Aiming a laser at an aircraft or its flight path is a federal crime and has caused dangerous, temporary blinding incidents among pilots. Thousands of incidents are reported to the Federal Aviation Administration each year.

On the ground, lasers can also cause eye damage, both short-term and long-term.

Lasers are categorized using a numerical system. Classes 1 and 2 are generally considered safe. Classes 3 and 4 can pose the potential for injury and require more safety precautions.

Early on, players in Gianforte's games mostly used red lasers they bought from a Danish company. Those were Class 2 lasers in compliance with EU regulations.

But as the games grew more competitive, players started turning to brighter, green lasers for an advantage, he said.

"I started seeing more of these green lasers, and they just kept getting brighter. That's when the accidents started happening," Gianforte said.

Gianforte contacted the University of Colorado Boulder, and a professor, who was previously a NIST researcher, put him in touch with NIST physicist Joshua Hadler, who leads our laser safety efforts.

During a 2013 research project, Hadler found that handheld laser devices are often inaccurately labeled. These devices can be far more powerful than the labels on the packages indicate.

"The green lasers are so popular because our eyes are most sensitive to green. People want that brighter light," he said. "They're also potentially more hazardous because of the nature of how the light is generated. The green lasers are made with technology that involves multiple laser wavelengths, some of which we can't even see."

Most green lasers work by using infrared laser light to generate the green light. Some of these green lasers have been known to allow the infrared light out as well. Although we can't see infrared light, those wavelengths are still collected by our eyes and focused on the retina. As such, the power of the infrared light adds to the power of the green light that is generated, potentially increasing the hazard the laser represents.

Safer Laser Practices

Hadler offered some practical suggestions to Gianforte. NIST does not have a regulatory role in laser use, so any suggestions are completely voluntary for the players and game organizers.

One idea he offered was to place a cardboard ring around the table to reduce the risk of laser light escaping the edge and hitting a child who might be browsing nearby.

Hadler also said game organizers could consider buying a handheld laser power meter to check each laser device at the door. These cost a few hundred dollars, so it may not be practical for individual game players. For organizers managing multiple games, though, a meter could be a practical investment in safety.

Gianforte's group has since banned all green lasers from its games - and a few area clubs have followed suit.

After their initial conversation, Gianforte interviewed Hadler. The resulting video was published online to raise awareness among the gaming community.

Gianforte said he got some pushback from the players at first, but participants are coming around to the new safety measures.

"I think a lot of people were under the impression that, well, if this is legal for me to buy, it must be safe. But it's up to you, the consumer, to use that laser responsibly," he said.

Hadler said he hopes participants who view the video can take practical steps to reduce their risks.

"You really need to understand that what you're working with may be potentially hazardous," Hadler said. "Some of these devices, if they're too powerful or the intensity is too high, they can cause injury from even a momentary exposure."