From 42 to NaN: the real stories behind LAN's numbers

Updated 26 October 2026 · by marcojlv

In LAN: Letters against Numbers the numbers aren't just enemies: many are nods to mathematics, computing and pop culture, and their quirk in the game has to do with what they mean outside it. The 404 vanishes. The 255 overflows. The 365 renews itself every year. Here is the real story behind each one.

Heads-up: several of these numbers appear quite high up in the game. We describe their quirk in one sentence; if you'd rather find out by playing, just read the history.

From mathematics

0, the number that took inventing

That "nothing" could be a number is far from obvious. Many cultures used a gap or a mark for empty positions, but treating zero as a number with rules of its own is credited above all to the Indian mathematician Brahmagupta, who in the year 628 explained how to add, subtract and multiply with it. In LAN the 0 is "null": the first hit it takes does nothing to it. And when it dies, sometimes, it lets something much bigger through.

∞, infinity

The ∞ symbol, a sideways eight, was introduced by the English mathematician John Wallis in 1655. Infinity isn't a number like the others, but the idea of something without end. In LAN it's a boss that slips in when the system "crashes" as a zero dies, and when it falls it splits into two zeros that have to fall together. By the way: the game's 8 honors the resemblance and, now and then, lies down and rolls like an ∞.

π, the letter posing as a number

Pi is the ratio of a circle's circumference to its diameter: 3.14159… and it never repeats. It's irrational and, what's more, transcendental. William Jones first used the π symbol for it in 1706, and Leonhard Euler made it popular; it has its own day on March 14 (3/14). In LAN, π moves in waves, like a sine function, and it has a twist: since π is really a Greek letter, it deals literary damage and shrugs off literary damage well.

√2, the root that broke the rules

The square root of 2 (1.41421…) is the diagonal of a square with side 1 and, by tradition, the first number shown to be irrational: it can't be written as a fraction. Legend credits the discovery to Hippasus of Metapontum, a Pythagorean, though there is no firm evidence. In the game, the "Root" does what its name suggests: its shots leave your letters rooted in place, unable to move or attack.

e, the number of growth

The number e (2.71828…) shows up in everything that grows continuously: compound interest, populations, radioactive decay. Jacob Bernoulli came across it in the late 17th century while studying compound interest, of all things, and Euler gave it its name. In LAN, e never stops growing: its health rises every second it stays alive, and its size with it.

i, the imaginary unit

i is the number whose square is −1, something impossible with everyday numbers. For centuries it was viewed with suspicion (hence "imaginary"), but today physics and engineering can't do without it. In the game, i is real only half the time: while it's imaginary, only literary attacks hurt it.

φ and Fibonacci, the golden ratio

The Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21…) adds the two previous numbers each time. Leonardo of Pisa, known as Fibonacci, made it popular in his Liber Abaci of 1202, with a puzzle about breeding rabbits. Divide each number by the one before and you get closer and closer to φ (1.618…), the golden ratio, linked to the spiral seen in shells and sunflowers. In LAN, φ comes in on a spiral, and the Fibonacci boss shows up at heights that are numbers in the sequence: 1,597, 2,584, 4,181… meters.

17, the indivisible prime

A prime number can only be divided by 1 and by itself. 17 is one of them, and in Italy it is considered unlucky: in Roman numerals, XVII can be rearranged as VIXI, "I have lived", which was carved on tombstones. In LAN, the 17 is indivisible another way: area damage doesn't affect it.

5!, the factorial

The factorial of 5 is 5 × 4 × 3 × 2 × 1 = 120, the number of ways to order five things. The exclamation-mark notation was introduced by the French mathematician Christian Kramp in 1808. In the game, 5! steps down from 5! to 4!, 3!, 2! and 1! as it loses health, and each step makes it faster.

½, ¼ and ⅛

The simplest fractions, and in LAN also the most literal: when a ½ dies, two quarters take its place; when a quarter dies, two eighths.

The symbols: +, ×, ÷, = and Σ

Operation signs are younger than they look. The + first appears in print in a commercial arithmetic by Johannes Widmann in 1489. The = was invented by the Welshman Robert Recorde in 1557 because, as he wrote, no two things can be more equal than two parallel lines. The × was popularized by William Oughtred in 1631, and the ÷ appeared in 1659 in a book by Johann Rahn. The capital Σ for sums became standard with Euler in the 18th century. In LAN, symbols don't attack: they help numbers. The + shields them, the × doubles their damage, the ÷ weakens your nearby letters, the = links two numbers so they share every hit, and the Σ heals the ones around it and swallows small ones.

From computing and the internet

404, "not found"

The 404 Not Found error is what a web server answers when the page you ask for doesn't exist. Codes starting with 4 mean an error on the asking side. A legend says the name comes from a "room 404" at CERN, where the web was born, but it's false: Robert Cailliau, who created the web with Tim Berners-Lee, has denied it several times. In LAN, the 404 vanishes for two of every five seconds, and while it's gone, nothing reaches it.

500, "internal server error"

The 500 is a server's generic error when something breaks inside and it can't say what. In the game, the 500 freezes with a loading spinner, jumps forward like a laggy connection and throws error windows that lock up your letters.

127, "localhost"

The address 127.0.0.1 is the one a computer uses to talk to itself, known as localhost. What you send there comes back to you. In LAN, its shots come back to heal it, and on low health it goes home, to the top of the board, to recover.

255, the overflow

A byte is 8 bits and can hold 256 values, from 0 to 255. Add 1 to 255 and you don't get 256: you're back to 0. That overflow has caused famous bugs, like the broken screen of Pac-Man's level 256, where the level counter wrapped around. In LAN, the first time the 255 reaches 0 health it overflows: it comes back at full health and spills a handful of small numbers.

1337, the language of the elite

1337 reads as leet, from elite. Leetspeak was born on 1980s BBS forums, where "elite" users had access to special areas, and it means writing with numbers or similar-looking symbols instead of letters: 1 for L or I, 3 for E, 7 for T. Letters written as numbers in a game of letters against numbers: it had to be there. In LAN, its shots "hack" the letter they hit and leave it unable to attack for a few seconds.

2048, the merging game

2048 is the puzzle game that Italian developer Gabriele Cirulli, aged 19, wrote over a weekend and released in March 2014: you slide tiles, and equal ones add up until you reach 2048. It went viral within days. In LAN, the numbers in this group arrive as tiles and, if two equal ones get close, they merge into one worth double, with their health added.

NaN, "not a number"

NaN (Not a Number) is what a computer returns when an operation makes no sense, like dividing zero by zero. The IEEE 754 floating-point standard defined it in 1985, and it has a quirk every programmer knows: NaN isn't even equal to itself. In the game, numeric damage passes straight through it, and the letter it hits deals no damage for a few seconds: it's contagious.

From culture and everyday life

42, the answer to everything

In Douglas Adams's The Hitchhiker's Guide to the Galaxy (which began as a radio series in 1978), a supercomputer spends seven and a half million years working out the answer to life, the universe and everything. Its answer: 42. Readers have spent decades looking for a hidden meaning, but Adams made it clear in 1993: it was a joke, he wanted an ordinary number and picked that one. Even so, 42 kept surprising people: in 2019, mathematicians Andrew Booker and Andrew Sutherland finally found how to write it as a sum of three cubes, a problem open since the 1950s. It is (−80,538,738,812,075,974)³ + 80,435,758,145,817,515³ + 12,602,123,297,335,631³. In LAN, the 42 is the boss of every 100 meters, and at half health it splits into four 2s: 4 × 2.

7 and 777, luck

7 is a lucky number in half the world, and triple seven is the slot machine jackpot. In LAN, the 7 dodges some of your attacks, as if it were lucky, though your taps never miss. And the 777 is a machine with reels that doesn't attack: beat it before it escapes and it pays out a pile of diphthongs. No betting of any kind.

13, bad luck

In English-speaking countries the unlucky day is Friday the 13th; in Spain and much of Latin America, it's Tuesday the 13th. The fear of the number 13 even has a name: triskaidekaphobia. In LAN, the 13 brings a black cat that crosses your front row: the letters it passes miss half their attacks for a while.

60, 360 and 365: keeping time

An hour having 60 minutes and a circle 360 degrees is inherited from the astronomers of Babylon, who counted in base 60. In the game, the 60 is a countdown bomb that explodes when it reaches zero; the 360 turns all the way round and hits every letter around it; and the 365, if you leave it alive too long, starts a new year and is back at full health.

99 and 100: almost

Who hasn't stared at a download stuck at 99%? In LAN, the 99 is exactly that: if it survives a few seconds, it completes and becomes the 100, which arrives with a shield and stamps a "100" on you that hits like three blows.

666, the Beast

666 is the "number of the beast" from the Book of Revelation, and from there it has found its way into countless films, albums and memes. In LAN it's a big boss, with horns, that shows up at 666 meters and every 666 meters after that.

1000, a thousand

A round number for a round boss: it shows up at 1,000 meters and, as it loses health, its digits fall off and keep fighting as zeros.

What about the rest?

Some of LAN's numbers are nods to memes, sport and film, and the game deliberately left them as plain numbers, with no one's name or face: everyone can recognize their own. To meet them all (and their quirks), there's nothing like climbing: start with getting started in LAN or go over the bosses and how to beat them.