The original script was titled "Cherries" and features three fathers as the leads. Leslie Mann's character was later changed to a mother.
The film was originally titled "Cherries" during development in 2012. When production began, it was changed to "The Pact". It was renamed "Blockers" in October 2017, when the film was in post-production and the first trailer was released.
This film was produced by Evan Goldberg and Seth Rogen, who were creative forces behind Superbad (2007). "Superbad" is a film about three high-school friends who try to have sex before graduation. A very similar story to "Blockers," except "Superbad" features male protagonists rather than female.
The film's title and posters are a reference to the act of "cock blocking"; the rooster icon was removed for advertising on broadcast television and cable networks that objected, with only the Blockers text being shown.
When Mitchell, John Cena's character, sneaks into Cathy & Ron's house while they are playing blindfolded, the sfx & water rings in the glass when Ron approaches Mitchell's hiding place are a clear nod to Jurassic Park (1993).