Dwarf Fortress
Dwarf Fortress
[Cueball sits at a desk with a computer, hands on the keyboard, talking to an unseen observer.] Cueball: If the corporate surveillance state monitors and controls every aspect of my life... Big Brother: We do. Cueball: And I play Dwarf Fortress all day... Big Brother: You do. Cueball: Then you're effectively Dwarf Fortress players watching your dwarves play Dwarf Fortress. Big Brother: ... Oh God. [Caption below the panel:] Big Brother realizes he's trapped in the most tedious possible Hell.

This comic is a reaction to the recent reveal of a U.S. electronic telecom surveillance program called PRISM , run by the NSA . There is a Guardian article about it. PRISM, leaked by a former NSA official, incited some controversy since it provides government access to private data (e-mails, videos, chats, file transfers, etc.).
Dwarf Fortress is a freeware strategy game in which the player builds a civilization by giving orders to — as opposed to directly controlling — a group of dwarves. It is famous for having a very detailed simulation of its world and for allowing deep micro-management (as well as an incredibly steep learning curve).
"Big Brother" means "a tyrannical government body that constantly monitors all its citizens." The term comes from the classic dystopian novel Nineteen Eighty-Four by George Orwell, wherein propaganda videos are narrated by an actor with the stage name of Big Brother and the dystopia's surveillance system is said to be monitored by Big Brother himself.
Cueball has a discussion with Big Brother ("corporate surveillance state"), in which he mocks Big Brother's interest in the inconsequential activity of playing a video game ( Dwarf Fortress in particular) by drawing a parallel between Big Brother's omniscient surveillance of Cueball and Cueball's omniscient surveillance of the dwarves. Big Brother appears to be mortified when it realizes the accuracy of Cueball's comparison.
Informally, a system exhibits Turing-completeness when it is theoretically capable of executing any algorithm. One of the simplest Turing-complete systems is the Turing machine , a device that manipulates symbols on a strip of tape according to a table of rules — it can be proven to have the same capabilities as any ordinary programming language. Other very simple systems include Rule 110 , lambda calculus , Conway's game of life , and Brainfuck . The reason we don't work with these is because they're a real pain in the ass. Would you rather build a network of spaceships that collide with each other to simulate the successor function, or just write i := i + 1 ?
A common CS nerd challenge is to prove the Turing-completeness of a system that wasn't intended to be that way — games in particular. The usual way to do this is to construct a Turing machine simulator within the system. It has been done for Dwarf Fortress , (infinite) Minesweeper (pdf), Magic the Gathering , Little Big Planet , Minecraft ( another Minecraft example ) 1 , Pokémon Yellow (through the elaborate use of many in-game glitches) and 3D chess . These kinds of proofs often involve formulating ridiculously complex creations just to simulate a little machine writing symbols on a tape! 2
Finally, Randall makes a crack that users will try to nest their Turing-complete computers; after finishing his Turing-complete Dwarf Fortress computer, someone else will try to make the Dwarf Fortress computer run Minecraft (a highly inefficient process that would be a nightmare to coordinate, and would run incredibly slowly).
1 The youtuber legomasta99 even built a whole programmable PC in Minecraft as can be seen here .
2 Technically, a computer is not really Turing-complete. A Turing-complete system has to have unlimited space, and that's not possible for a memory-limited computer or any software running inside it. But even if we don't have access to Turing-completeness, we can build a theoretical machine and show how it can be extended indefinitely. In a few of the games, we prove Turing-completeness in infinite variants.
[Cueball sits at a desk with a computer, hands on the keyboard, talking to an unseen observer.] Cueball: If the corporate surveillance state monitors and controls every aspect of my life... Big Brother: We do. Cueball: And I play Dwarf Fortress all day... Big Brother: You do. Cueball: Then you're effectively Dwarf Fortress players watching your dwarves play Dwarf Fortress. Big Brother: ... Oh God. [Caption below the panel:] Big Brother realizes he's trapped in the most tedious possible Hell.
