A mate of frontman Mike Kerr's encouraged him to develop this song. He told Kerrang: "We were on tour with a band called Bass Drum of Death and their singer John Barrett is a good friend of ours. One night we were exchanging demos and showing each other ideas we were working on, and I showed him the first idea for this. Initially I wasn't keen on it, but he kinda of convinced me that we should do something on it."
The track has an unexpected influence. "We were going for a Daft Punk thing quite a lot and trying to f--k with the rock thing, I guess," Kerr told NME. "What would Daft Punk do if they wrote a rock tune?"
Mike Kerr sees this as the starting point for the How Did We Get So Dark? album. He told The Sun:
"There were lots of tunes written before this one but when Lights Out revealed itself and came together as a tune, that felt like a breakthrough moment. It felt like we had come up with a tune that had topped anything we'd done before. I guess aesthetically as well - the texture, all the elements of it, the more sophisticated production and the song. That set the tone for the rest of the album."
This was Royal Blood's second #1 on Billboard's Mainstream Rock chart, following "Little Monster" which peaked on the tally in July 2015.