Something like a definition
We can speak about interactive fiction in a broad and a narrow way. In the broad way, interactive fiction pieces are works of fiction that require a more active participation by the reader than merely reading them. Examples are text adventures, choose-your-own-adventure books, hyperfiction (fiction that your browse using hyperlinks), and even such strange literary experiments as Queneau's "Cent Mille Milliards de Poèmes". Roleplaying games are not interactive fiction even in the broad way, since a roleplaying game is not a work of fiction.
However, when we speak about interactive fiction, we normally speak about interactive fiction in the narrow way. This is a subset of the broader definition in that it encompasses works of fiction that have all of the following characteristics:
- The work is software, and is read using a computer.
- The computer simulates a model world.
- The reader interacts with the work by typing sentences, which are processed by a parser.
The second characteristic is that the computer simluates a model world. Often, this involves at least a number of locations, linked up in some way, and object than can be present in these locations. The computer then keeps track of where every object is in the model world, and based on these locations the player character can or cannot see or take the object. In general, the computer will track much more than this (whether objects are inside each other, whether doors are open or locked, whether objects are clothing, whether they are animate, whether they are sources of light, whether they are transparent, whether they are hidden, and so forth). The computer uses this model world to decide what effect a command by the player has. So if I type "take key", the computer will check whether the key and the player character are in the same location, whether this location is lit, whether the key is not hidden, and so forth - if all conditions have been met, it prints something like "Taken.", and changes the location of the key.
In this sense, interactive fiction works very differently from choose-your-own-adventure books or hypertext: in those, all options have been thought up by the author and it has been explicitely stated what text must be printed in each case. In interactive fiction, the author often defines only general aspects of the world, and lets the computer generate appropriate responses to many standard actions.
The third characteristic is that the reader interactis by typing commands, and the computer interprets these using a parser. What is a parser? It is the piece of software that changes the commands of the player into commands that the computer can understand. As a player, I might type "get key", "take key", "get the key", "take the key", "take the bronze key", and so forth, and I'd want all of them to have the same effect. The parser is the piece of software that changes all of these into the same basic command that the computer can understand (and which is probably something of a form that the player wouldn't!). The parser may also do such things as ask the player to disambiguate his command. "Take key" "Which one, the bronze key or the iron key?" "Bronze"
In practice, computer-based choose-your-own-adventure is also sometimes called 'interactive fiction', mostly because it is often made with the same programming tools.
Yes, the old text adventures fit nicely within the narrow definition of interactive fiction, and they are where the genre came from. Collosal Cave / Adventure, the Zork trilogy - these are the first works of interactive fiction. In their time, they were a big commercial success. Infocom, the makers of Zork, made the critically most acclaimed pieces that got to have much more story and depth, better writing and a better parser than the old games - some titles from this period where A Mind Forever Voyaging, Trinity and Suspended. Many of these titles where pretty innovative, but the basic concept stayed the same: you collect objects and try to solve devious, very hard and often deadly puzzles. Solving puzzles unlocks new parts of the story.
Then the 90's came, interactive fiction lost its popularity to computer games with graphics, Infocom collapsed - and there would have been no post about the genre in this blog if that was were it ended, because I'm too young to remember the heyday of commercial IF.
The indie scene
But that was not were it ended, and it didn't end because of the internet. Through this wonderful web of ours, people got into contact which each other, and decided to start writing this stuff themselves. Two major languages for writing IF were designed - Inform and TADS (Text-Adventure Development System) - and people started writing their own games. The scene is quite alive. There are dozens of entries in the Interactive Fiction Competition each year.
And here is the interesting thing: although there is, of course, a lot of crap, the best of these independent pieces are in my humble estimation much better than the old commercial pieces. More daring, more like works of art, and - important for me - less focussed on puzzles.
Sounds familiar? Through the internet, people who liked X got to know each other, started talking about it, then started developing X on their own. These indie developers dared to think out of the box, and what they made was often much better and more interesting than what the commercial guys had to offer. Also, they started to put more emphasis on story and less on puzzles.
For X, 'role playing games' can as easily be substituted as 'interactive fiction'. The big difference, though, is that the roleplaying companies are very much alive, wheres the IF companies are very much dead.
So, this new stuff is good?
It is. From the brilliant Lovecraftian horror of Anchorhead to the brilliant narrative decpetion of Spider and Web; from the puzzleless Photopia to the budding narrativism of Slouching towards Bedlam; from the disturbing little one-room piece Shade to the dark and sinful Vespers; from the study in NPC design Galatea to the cruel political puzzle game Varicella; from the old school The Dreamhold to the logical time travel paradoxes of All things devours - there is a wide variety of great pieces.
And you can try it out today, because everything I just named is free. (Almost everything is, in the IF scene.) Perhaps this is the best place to start. Most of the best games are written in the Z-Code format (using the Inform language), and that site will tell you how to obtain one for your OS.
The above are all great pieces, but not all of them may be suitable for beginners. Varicella is very difficult; Photopia is very easy, but takes a lot of its power from not doing what IF is supposed to do (which you might miss if it's the first thing you play); Galatea is especially impressive once you've seen how difficult it is to create a convincing NPC. Those three might not make the best places to start.
If you like puzzles, The Dreamhold and Anchorhead are very good places to start. The latter is number 1 in the IF ratings, so it's a good place to start for everyone. Shade and Slouching Towards Bedlam aren't too difficult, and very good. Spider and Web is a work of genius, but sometimes a bit picky about which input it accepts, so you may have to try finding the correct verb now and then. If you like your puzzles logical and mathematical, try All things devours. Walkthrough for all these games can be easily found on the web.