Part 238: Chapter 238

In this post, I'm going to talk a bit about the differences between the original version of Adventure and the one we just played.

The original game, as has been said, was developed for the DEC PDP-11 computer and written in FORTRAN. This one was ported to Microsoft FORTRAN several times; the particular version we're interested in was made by Don Ekman for PCs in 1990. That version was itself ported into TADS (the Text Adventure Design System), one of the main programming languages for modern text adventures, by Dave Bagget in 1993. That version was used as a basis for Graham Nelson's Inform port (Inform being the other main language for modern text adventures), which we played, in 1994. There have been several revisions since then. As you can see, we're rather far removed from the original version, and many things have been changed or lost.

We already discussed this upthread, but the features that support disabling the game for multi-user systems weren't relevant for the PC port and were removed.

The original uses all-caps, and very ancient versions actually printed their output to a printer rather than a terminal. You could only use two-word commands, and it only paid attention to the first five letters of each. This necessitated the creation of a number of abbreviations; ne for northeast, for instance, since the game treats "northeast" and "north" as the same command. These abbreviations are now essentially universal in interactive fiction.

The original had a save function, but it actually worked more like a modern emulator's save states (although you only got one). You could quit/suspend the game, which would dump the entire memory (including the game code) to a file for you to restore later. You couldn't have multiple saves and mess around with things, but at least you could go to the bathroom or eat lunch. Of course, this would also reduce your score because the designers were heartless bastards. Inform does not allow the saving mechanism to be trivially interfered with, so this mechanic was not transferred. Instead, we get the standard save/load/undo states; this is one reason I played the Inform port, because a Let's Play thread is much easier to run if you have access to those abilities.

The original only gave you your score at the end or when you tried to quit, which made it somewhat difficult to tell why points were being assigned. This compounded the difficulty of things like losing points for not beating the game in a single sitting, because you wouldn't even know why you were four points short.

When you started the original, it would ask you if you wanted directions. If you said yes, it would print the following:

Naturally, you would lose points if you asked for instructions.

The dwarves were originally implemented as actual psuedo-NPCs with their own locations. This included the Pirate, who is occasionally referred to in the source code as the sixth dwarf. (There are five regular dwarves in the game, not seven as I implied early on during one of my gratuitous Dwarf Fortress references.) The dwarf encounter would be triggered if the dwarf's location happened to overlap the player's, and the dwarves would move around whenever the player moved. You could get more than one dwarf at once, which would be exceedingly dangerous. The Inform port simply rolls dice every time you move to see if a dwarf appears; there is a 1% chance that this will happen for every dwarf still alive. (This is why the dwarves appear less and less frequently as we kill them.) Similarly, the pirate has a 2% chance of showing up on every move until he appears, after which he is never seen again. This is a less direct simulation than the original, but produces a very similar effect from the standpoint of the player.

The magic words in the Inform version only work after you've visited the rooms they apply to. In the original, if you happened to know them you could teleport directly into the cave from the well house and never bother with the stream or the grate at all.

You could use the command RETREAT in the original, which would take you back to the last room you were in regardless of any messing with directions. You could also sometimes use the name of adjacent rooms to move to them, or alternative directions like DOWNSTREAM near the beginning. Most people were never even aware of these features, which is partially why they were quietly lost over time.

The original version actually had a very interesting hint engine. The game would keep track of how long you spent in certain locations (such as Witt's End), and if you were there too long it would offer you the chance to get a hint on what to do next. The hint would cost you some of your points, but would generally steer you in the right way to solve the puzzle.

The oyster clue in the final room originally said this: THERE IS SOMETHING STRANGE ABOUT THIS PLACE, SUCH THAT ONE OF THE WORDS I'VE ALWAYS KNOWN NOW HAS A NEW EFFECT. Notice the crucial difference: WORDS rather than curses. Our version makes the puzzle a bit easier. Reading the oyster counted as a hint, too, so the system would ask you if you wanted to lose points before telling you, essentially, "a command you may or may not have even entered now does something different than it did before which probably will help you in some undefined way".

Many of the error messages are different. Inform has its own error message library (including the "That's not a verb I recognise." message we saw so frequently). Graham Nelson also added several messages relating to blasting rocks out of the way (which we saw one of) as a sneaky way of hinting the last puzzle early on.

There are a few other differences, but those are the most important ones (although I am sure I have missed some). An extra little goodie for people who read this whole thing: some brave soul made a hand-drawn map of the entire cave, including all the insane twists. It may be seen here: http://www.spitenet.com/cave/.

Tomorrow, one more post where I blabber about the general history and impact of the game, and then we're done with the thread.