A very short rant about the meaning of the term 'fish puzzle'

July 07, 2026  

A brief history lesson for you.

Puzzup is an organizational software used for writing puzzlehunts. (Additional rants about Puzzup may be available at a later date.) One of the features it has is that lets you rate puzzle difficulty after testsolving, using a 1-6 rubric. Language here is mine for brevity:

  1. “Too easy”. Readily solved by existing tools. (nb: This line gets a little blurry when considering LLMs; this guideline refers more to things like cryptogram or sudoku solvers.)
  2. Easy. Straightforward puzzle with at most one aha. Most teams will solve this.
  3. Medium. Most teams will solve this in under 5 person-hours; competitive teams will solve it faster. (5 person-hours means five people working for an hour.)
  4. Hard. Competitive teams will solve this in under 5 person-hours; non-competitive teams may take longer.
  5. Mystery Hunt Hard. What people think of when they think “Mystery Hunt puzzle”; requires specialist knowledge, difficult insights, and a particularly long solve time.
  6. Too Hard. Too long or difficult to be included in Hunt (e.g. Ripple Effect).

I don’t know how long these ratings have been around. Puzzup is an evolution of an old, old, old piece of software; it started being called by its current name in 2021 (by Palindrome), where it was cloned from Puzzlord (a 2019 incarnation by Galactic), which itself was ultimately descended from Puzzletron (instantiated by Codex). The Puzzletron git repo has an initial commit “Initial import from Metaphysical Plant’s hunt software” on Feb 2, 2011 (presumably in preparation for the 2012 hunt). That and other early commits lead me to believe that the first incarnation of this software was developed by Plant in 2010 for the 2011 hunt. And in the last 16 years, someone came up with this 1-6 difficulty rating.

(Incidentally, we can also see what a bit of the old 2011 Puzzletron formatting looked like in the puzzle Piercing the Veil.)

In 2015, Team Random ran their incarnation of MIT Mystery Hunt, themed around 20,000 Leagues Under the Sea. Solvers dove to the bottom of the seafloor, with rounds themed around shoals of a Pod of Dolphins, a Treasure Chest, and so forth. One round was called the School of Fish round, and it was notable for two very specific reasons:

  1. It had 56 puzzles in it. (The second-largest round in the hunt had 9.)
  2. All 56 puzzles were extremely, extremely easy. In my opinion they would all get 1s (or at most 2s) on the Puzzup difficulty rubric.

(Hence the name “school of fish” for the round: it’s a large swarm of small things. Cute!)

This led immediately to the term “fish puzzle” to describe these extremely easy puzzles, and a “fish round” to describe a round with many extremely easy fish puzzles. This was a popular term, not least because School of Fish was very evocative. Reading through the reddit AMA about the hunt immediately after, many solvers commented positively on the round, and it is iconic enough to have broad recognition even today (I don’t think I could say the same for many other rounds in the same hunt).

But somewhere along the line, the fish began to mutate, in the dark…

I don’t know how to track these changes over time, but I know where the story ends: in the wrapup for the 2026 Mystery Hunt, Cardinality referred to the Kingdom puzzles (puzzles from the first half of the hunt) as fish puzzles. These are puzzles with difficulty ratings from 2 to 4. This definition was more or less immediately corrected by Benji, but it is emblematic of a wider definition drift I have observed: many people on a number of teams have begun to refer to these puzzles as fish.

This definition drift is utterly insane to me. Eleven years ago, a fish puzzle would be considered on the tougher side if it had an Easy (2) rating… and now it is common parlance to refer to Hard (4) puzzles as fish! This is not just Cardinality, either; I think this understanding of “fish” as “somewhat easier puzzle towards the start of the hunt” is far, far, far more common among solvers who only started hunting this decade. At some point, the original meaning was lost.

I am a linguistic descriptivist, but also I hate this. Change it back! You don’t need a special name to describe more approachable puzzles in the first half of the hunt! That’s just what most puzzles in the hunt are! Team Random did not invent the idea of easy puzzles in 2015! The whole thing that was interesting about that round – the whole reason that fish puzzles got a special term in the first place – was because all those puzzles were much, much easier than anyone thought would be possible in a Mystery Hunt! Cardinality already had a bunch of 1-2 difficulty we could refer to as “fish” – they were all in Terminus!

Is this why the hunt is ballooning in scope? (Probably not.) Gah! Don’t say “fish puzzle” unless you mean it!

Say it with me: fish means 1 to 2, not 2 to 4!