things that are turing-complete that shouldn't be

! ~ ~ ~ ~ ~ ~ ~ ~ -- ~ ~ ~ ~ ~ ~ ~ ~ !
computers are hiding everywhere
! ~ ~ ~ ~ ~ ~ ~ ~ -- ~ ~ ~ ~ ~ ~ ~ ~ !

normally we only expect things like programming languages or
computers to be turing complete so i always get a little excited
when i find turing completeness in other places

this is a list of things i've come across that have turned out to be
turing-complete even though they have no business doing computations

obviously your definition of "surprising" may vary
but this is my website so you're stuck with my opinions


magic the gathering

i suspect there are a lot of card/board game mechanics that are
turing complete but right now, as far as i know, MTG is the only one
it's been proven for.

magic has a lot of complicated rules for resolving card effects
so writing "programs" for the game rules to execute simply requires
choosing the right effects and putting the cards in the right order,
then you just follow the rules of the game and you get a
state machine that can implement any turing machine.

Magic: The Gathering is Turing Complete [8 pg]
video of the deck in action [22:53]


microsoft powerpoint

the linked video is worth a watch and the paper goes into more details
but basically, powerpoint animations and smart shapes are
complex enough to implement a turing machine

On the Turing Completeness of MS PowerPoint [pdf, 5 pg, 1.01 MB]
presentation [5:33]


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written by peter beard on 2026-03-19, last updated 2026-03-25
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