## Tetris Font | ## by Erik Demaine and Martin Demaine, 2020 |

**Tetris** is
among the best-selling (and perhaps best-known) video games ever.
We grew up playing the
Game Boy and
Spectrum HoloByte PC editions.
Erik is even a Tetris Master.
Nowadays you can play
in your browser
or on a Switch
or on PS4/PC/VR.

**Font design.** Each letter in this typeface is made up of exactly
one of each of the Tetris pieces:
(I),
(J),
(L),
(O),
(S),
(T), and
(Z).
Furthermore, the letter is designed so that it can actually be constructed
by stacking these pieces one at a time and be supported by previous pieces,
as in Tetris.
These designs were found by hand, aided by the
BurrTools software
which enabled searching for whether the Tetris pieces could fit inside
a candidate outline for a letter.
The piece colors roughly follow
The Tetris Company's standard colors,
or you can switch to black pieces.
The initial rotations follow the standard
Super Rotation System.

**Puzzles.**
In the **puzzle font**, the letters are at the correct rotations and
horizontal positions, and their vertical position represents their drop
sequence. Drop the pieces in your head (or via **animate**) to figure
out what letter is encoded.
•
Even without puzzle font turned on, in the **animated** font, you can
try to guess what the letter is before all the pieces have arrived.
•
One final set of puzzles: In the unanimated unpuzzle **black-pieces** font,
try to figure out how one of each Tetris piece perfectly packs that shape.
(This is the task that BurrTools is very good at.)

**Related mathematics.**
(Perfect-information)
Tetris is NP-complete,
meaning that it's computationally intractable to figure out whether you can
survive, or clear the board, given an initial board configuration and a
sequence of *n* pieces to come.
Similar results
hold for *k*-tris played with
*k*-ominoes
instead of tetrominoes. Most recently, we
analyzed the
complexity of Tetris with few rows or columns; this font appears
in that paper.

**Acknowledgments.** This font was inspired by a collaboration with
Alex Streif and Kate Jones of
Kadon Enterprises
during BRIDGES 2017,
where we started designing a font using just 5 pieces:
the “free
tetrominoes” where S is the same piece as Z and J is the same
piece as L.
Relatedly, Kate Jones designed other polyomino
fonts included in some Kadon manuals.
By contrast, this typeface aims closer to the rules of Tetris,
where reflection matters and the pieces must stack and be supported.

Check out other mathematical and puzzle fonts. • Feedback or not working? Email Erik. • Source code on GitHub.