It’s Sunday, it’s almost 2025, and the back of my head has hurt for the last 4 days, but it’s not going to stop me from writing this entry about Oxford’s word of the year: brain rot. Apparently, the first recorded use of the term was in 1854, in “Walden,” Henry David Thoreau’s classic account of moving alone to a cabin in the woods to live a simple lifestyle. He talks about society’s tendency to devalue thinking that has complexity and nuance and instead favors simplicity as a decline in intellectualism: “While England endeavours to cure the potato rot, will not any endeavour to cure the brain-rot – which prevails so much more widely and fatally?”

Since 1854, the term brain rot has been used in various ways… Oxford now defines it as “the supposed deterioration of a person’s mental or intellectual state, especially viewed as the result of overconsumption of material (now particularly online content) considered to be trivial or unchallenging. Also: something characterized as likely to lead to such deterioration.” In 2024, usage of the term has grown by 230%. It’s a sign of how language is evolving in the social media age, which is increasingly evident, considering Rizz took the crown in 2023.

Brain rot has taken on a new level of importance as it’s resurfacing to characterize mediocre social media content derived from memetics that Gen Z and Alpha gravitate towards. But by whose standards is the content medicore? Are we just old? The discourse on brain rot has particularly interested me because people love creating it on Castle.

To many, Castle has been taken. When people open the app, they see a feed of prevelant trends in brain rot culture: burger making, sprunki character builders, friday night funkin, skibidi toilet, with sprinkles of “good games.” But I’m not sure it’s a bad thing. Castle has brain rot content specific to the platform, that was created with no intent of becoming brain rot, like ending games, fish bowls, chase decks, etc. It’s easy to make ” bad ” content, and the remix feature on Castle makes it easy for them to spread and become trends. Younger players don’t see brain rot as brain rot, mainly older ones do. Brain rot is a thriving scene on Castle. Brain rot is how you win Castle’s algorithm.

In an attempt to boost our retention, which we assumed could be improved by showing “good games” in the first session for new players, we ran an experiment. After curating a list of games or “decks” that we thought were good based on our social engagement and gameplay standards, we made them the first decks new players see in their feed after the three hard coded ones. It hurt our retention. There are many reasons why this is the case that I won’t go too deep into in this entry. However, we were able to conclude that taste is subjective; what matters is personalization.

Castle has grown to over 2 million players, and we’re at a stage where helping people find their niches is becoming increasingly important for the health of our community. Right now, we have much to improve around how we segment our players so they see what interests them the most. There are negatives and positives of algorithmic segmentation that I’ll break down in a different entry. We can point to platforms like Instagram, Roblox, and Twitch as services that have “figured this out.” It’s an incredibly hard problem that we’re picking away at, but we ultimately want to get to a state where if you don’t like brain rot and want to find “the good stuff” or vice versa, you can find your community.