There’s nothing “retro” about Interactive Fiction

Sometime back in the early 1980s I booted the family computer (a TRS-80 Model I, if memory serves) and loaded a new program we had just acquired. In flickering green letters a strip of text appeared across the top of the screen:

I’m in a forest
Obvious exits: NORTH SOUTH EAST WEST
Visible items: Trees

Then below that:

A voice BOOOOMS out: Welcome to Adventure International’s Mini-Adventure Sampler! This is a small but complete Adventure. You must find the 3 hidden Treasures and store them away! Say: score to see how well you’re doing! Remember you can always say HELP
WHAT SHALL I DO?

This was a free sample of “Adventureland”, the first in a series of about a dozen text adventure games by Scott Adams and his company Adventure International (that’s not the same Scott Adams responsible for Dilbert). As the name implies a text adventure game had no graphics - all you got were text descriptions of what happened in the game world. To play a game you typed in commands like “GO NORTH”, “GET SWORD”, “KILL TROLL”, and “EAT APPLE” and the game would respond to your instructions. Some people reckon that text adventure games were a bit like those “choose your own adventure” books but that’s a pretty superficial comparison because the level of immersion in a text adventure far exceeds what is possible in one of those books.

How is it that I remember the rather unspectacular opening words of Adventureland? Well, I didn’t. Nearly thirty years later I’m sitting here looking at Adventureland on a present day computer. You see, the text adventure game never went away - while it stopped being commercially viable interest in the genre continues in an online community of enthusiasts. In the process the games gradually became more sophisticated and literary, and text adventures became Interactive Fiction (IF) - a title that better reflects the tendency to broaden the stories beyond swashbuckling swords-and-sorcery themes to those with a much wider range of styles. The Interactive Fiction of today bears little resemblance to the sparse writing of the early text adventures, like that quoted above.

What is Interactive Fiction?

In essence, IF presents an imaginary world that the player can explore by giving written commands to their proxy in that game world. The computer acts as narrator, referee, and the player’s character. The experience of interacting with your fiction varies from story to story; some stories are essentially a stream of progressively more difficult puzzles while others are cleverly conceived dramas that immerse the player in a dynamically unfolding plot.

In the beginning

The first ever computerised text adventure was called simply ‘Adventure’ or sometimes ‘Colossal Cave Adventure’, modelled on a real cave system that was known to the author Will Crowther. The first version was written in FORTRAN on a DEC PDP-10, probably during 1975. It quickly spread through the computing community, which was then mostly at universities.

In 1976 Don Woods stumbled across the program on one of the computers at Stanford University. Intrigued, Woods contacted Crowther and got permission to further develop the game. Later that same year the expanded game was rewritten in the C language and made available on Unix. Adventure then escaped onto the internet (where you can still download it to play on just about every computer imaginable).

Zork

In an early open-source effort, programmers started to tinker - expanding the Colossal Cave by adding new locations and characters that were totally unfamiliar to Crowther and Woods. This gave rise to the first Zork adventure and the Infocom company. The significant thing about Zork is that although programmed in ZIL (a variant of Lisp) it was compiled to run within a virtual machine - the Zork Machine, or more commonly Z-Machine (in much the same way the Java compiles to bytecode that can be run portably, ZIL compiled to Z-code). This was a clever commercial decision because at the time there was a wider variety of microcomputers than we have today - remember the Amiga and Commodore, Sinclair, TRS-80, Amstrad, and Electron? Apple and IBM were there also. So to make their entire catalogue of games available on any computer platform all Infocom needed to do was port the Z-Machine program (called the interpreter) and the games would run.

Point-and-grunt

The transition from text-only to graphical adventures was led by the Sierra company with their excellent King’s Quest and Space Quest series of games, and not forgetting the more “adult-oriented” Leisure Suit Larry series (incidentally, Leisure Suit Larry started out as a text-only game rather unsubtly called Soft Porn Adventure).

Eventually this led to games where control of the game relied less and less on typing at the keyboard. Inevitably this changed the nature of the games, leading to more reliance on action in games like the first-person shooters (the breakthrough games here being Wolfenstein 3D then Doom.

So the text adventure is the direct ancestor of today’s graphical adventure and first-person shooter games, and when adventure games got graphics the commercial market for the older style of text-based games collapsed. But just because people didn’t want to pay for text adventures didn’t mean that no one wanted to play them.

Getting Inform-ed on the Z-machine

Enter Graham Nelson from the University of Cambridge (now of Oxford) who got hold of the Z-Machine specification and in 1993 wrote a new language and compiler for it, which he called Inform. Inform is an object-oriented fully functional programming language that just happens to produce its compiled programs as Z-code.

TADS

Meanwhile the Text Adventure Development System (TADS) had been available since the late 1980s and was probably the earliest Interactive Fiction authoring system available to hobbyist programmers. TADS is still available and continues to be developed.

TADS and Inform are the most popular platforms on which Interactive Fiction is written today, and they are largely responsible for the enduring interest in Interactive Fiction.

First published: PC Update June 2006