Chris Lopes and Caleb Stephens didn’t have many friends for years. Growing up 1,000 miles apart, the two had been diagnosed with Autism Spectrum Disorder when they were younger and always found social interactions uncomfortable. The exception, for both, had been their brothers. But they both lost their brothers, and the only real friendships they’d had.

Like many people with autism, they turned to gaming and meeting people online.

“I’ve...