The Floor Is Lava, a limited time mode based on the childhood game where you jump from couch to counter and accidentally break a lamp while trying to avoid the imaginary lava on the floor, is coming to Fortnite.
This information can be seen via the in-game news feed, which states: “Get to high ground or build above the lava that’s overtaking the island.” The image notes that the LTM is “coming soon,” and it’s expected to drop with the upcoming v8.20 update, though no specific date has been announced.
Source: IGN.com The Floor Is Lava Coming to Fortnite as a Limited Time Mode