Platform, device version and operating system:
iOS & Steam
What you were expecting to happen, and what actually happened:
Two Delve rooms have had an error in their text ever since they were introduced in the second wave of rooms: Infernal Den and Volcanic Shaft. Both use the word “gains” when they should say “gain”. However, I actually suggest changing Infernal Den’s text to match that of Lava Cracks, which has the same room trait.
I did report this on Discord, but I guess it got missed, so here’s an official bug report.