🐟 Deadfish — The Language With Only Four Commands and No Error Shame

What is Deadfish?

Deadfish is a deliberately simple and slightly absurd esoteric programming language created as a joke. It has only four instructions: increment, decrement, output, and reset. The name "Deadfish" comes from the idea that the language has almost no intelligence or capability — like trying to teach a dead fish to code.

Despite its minimalism, Deadfish became popular in esolang culture because it is easy to learn, fun to experiment with, and can still compute values using its primitive memory model. The humor comes from how inconvenient basic tasks become.

Specs

Language Type: Joke / Minimalist

Creator: Jonathan Todd Ross (attributed)

Execution Model: Single integer register (0–255)

Instruction Count: Only four commands

Purpose: Humor and experimentation

Instructions

i → increment
d → decrement
s → square value
o → output ASCII

The interpreter also resets the value to zero automatically if it exceeds 255 or becomes negative.

CODE EXAMPLE (Hello World)

Deadfish "Hello World" output depends on character codes. A simplified example is:

iiisiiiisdddoiiisdddoiiisdddo

This prints text based on value manipulation.

(Actual full “Hello World” programs are significantly longer and look repetitive.)

How It Works

The program maintains a single integer variable.
Each command mutates this value.
When the program outputs (o), it prints the current value as an ASCII character.
The s instruction can rapidly increase values but makes planning sequences tricky.
Because overflow automatically resets to zero, arithmetic becomes unpredictable unless carefully planned.

The challenge is creating meaningful output with only tiny operations.

Strengths

Incredibly simple to learn.
Easy entry point into esolangs.
Fun for puzzles, experimentation, and generating weird ASCII art.
Good teaching tool for demonstrating Turing minimalism.

Weaknesses

Very slow to generate meaningful results.
Tedious for large programs.
No built-in loops, variables, or structure.
Easily produces nonsense or unintended output.

Where to Run

Deadfish interpreters exist on:

TIO.run
GitHub repositories
Browser-based toy consoles
Esolang playground websites

Some versions include visualizers to track value changes.

Should You Learn It?

For real-world programming: No

For fun, jokes, or curiosity: Yes

For teaching minimal syntax and value manipulation: Useful

For serious readable code: No way

Summary

Deadfish is a tiny esolang defined by humor, minimal syntax, and chaotic behavior. With only four instructions and a memory model that auto-resets values, it turns even simple output into a puzzle. While impractical, Deadfish remains a beloved entry-level esolang — proving that programming languages don’t need complexity to be entertaining.