Writing in Inform

WI §7.1. Actions

"Actions" are what we get if we try to break down a narrative into its irreducible parts. We might casually say that we are "going shopping", but this involves many smaller steps: going north, going east, entering the shop, examining a loaf of bread, taking it, giving money to the baker, and so on.

An action is an impulse to do something. This may or may not be a reasonable aspiration, and may or may not be achieved. The player's exploration of an interactive fiction is made by a sequence of actions, so much of the designing process comes down to responding to these actions.

We write actions using present participles. For instance, if the player types "take napkin" or "get the napkin" or something similar then the resulting action would be written as:

The details of what words the player actually typed are unimportant to us: we deal only in actions.

Every action ends in success or failure. In this context, success means only that the player's intention has been fulfilled. If the player sets out to take the napkin, but finds a million-pound banknote in its folds instead, the action will be deemed to be a failure.

The testing command ACTIONS causes Inform to log every action as it happens, and what its outcome is. (ACTIONS OFF turns this off again.) For instance:

A good way to get a sense of the constant flow of actions is to use this command and then wander around an existing work, trying things out. ACTIONS can also give an insight into the web of rules governing play: there are more than ten different ways an attempt to take something can fail, for instance.

WI §7.2. Instead rules

An action is ordinarily handled by running it through Inform's extensive rulebooks of what might be called normal behaviour. An action such as "taking the napkin", for instance, will be run through numerous checks to see if it is physically reasonable, and then provided all is well, the napkin will be moved into the possession of the player.

Instead, though, we can bypass the rules to do with an action and do something else:

This is an example of a "rule": a set of circumstances followed by a list of instructions. When those circumstances apply, the instructions are carried out. In the case of an "instead" rule, after this is done the action is immediately ended (and counts as a failure, since the original intention has been thwarted).

A friendly alternative can be used when there is only a single instruction, as here: in such rules the colon can be replaced with a comma. Thus:

WI §7.3. Before rules

Despite what was said in the previous section, instead rules do not quite bypass all of the usual rules. Inform knows that certain actions require light: for instance,

and if it is dark then none of these actions will be allowed, and any instead rules about them will not even be reached. Similarly, Inform knows that most actions require physical access to their objects: so "taking the napkin" would be blocked if the napkin were, say, inside a closed glass bottle, whereas "examining the napkin" would not. So an instead rule can only take effect if the action has already passed these basic reasonability tests.

"Before" rules genuinely precede checking of any kind. They also differ from instead rules in that they do not automatically stop the action in its tracks. Rather, they are provided as an opportunity to ensure that something else is done first. For example:

whence

We have seen that instead rules automatically stop actions, whereas before rules automatically allow them to continue. We sometimes want to change this. The magic word "instead" can therefore be tacked on to any instruction in a before rule, and will have the effect of immediately stopping the action at that instruction. Thus the following two rules are (almost) equivalent:

It is also possible to be explicit about stopping the action:

Finally, we can prevent Inform from stopping the action when it otherwise might:

As a general principle, it is good style to use instead rules whenever blocking actions, and before rules only when it is genuinely necessary to do something first but then to continue: in fact, it is good style to use "stop the action" or "continue the action" as little as possible.

WI §7.4. Try and try silently

Chapter 2 noted that surveys of Inform source text showed that the three most popular phrases used by authors are "say", "if" and "now". The fourth most popular is "try", which allows us to trigger off actions ourselves, rather than waiting for the player to type something which generates them. Thus:

The word "try" is intended to make clear that there is no guarantee of success. For example:

could go wrong in any number of ways - perhaps the door is closed already, perhaps it is not openable, perhaps somebody has wedged it open. It would be safer to write:

There's no need to say anything if closing didn't work, because the closing action will have done that already. A neater approach still is to use:

So now we have:

And this is neater because it won't produce a pointless "You close the front door." message.

WI §7.5. After rules

There is pleasantly little to be said about "after" rules. If an action has survived all the rules in its way, and has actually succeeded, then we need to give the player a response which acknowledges this. Inform's normal rules will be sufficient to say something undramatic: for instance, if "taking the napkin" has succeeded then it will reply "Taken." to the player.

An after rule is an opportunity to say something more interesting:

(Well, slightly more interesting.) After rules automatically end the action (as a success), which is what we would want in the above case. Allowing it to continue would simply result in "Taken." being printed as well. However, should we really need to do something and then carry on:

WI §7.6. Reading and talking

A few actions apply not to items alone, but also involve what might be called conversation. The first is the one used for looking things up in books (which is conversation of a kind, even if the author is not present): "consulting ... about ...". For example,

Note that what follows "about" here is a piece of text in double-quotes, and not the name of something. It can be almost any text at all, and in fact we shall later see (in the chapter on "Understanding") that we can match complicated patterns of words, too.

Similar actions are used for conversing with people:

These would be produced by commands like "ask sybil about verses", "tell sybil about persians" and "answer i am mad". Answering is little-used except that it also catches commands like "sybil, something unrecognized", which inexperienced players sometimes type. Asking and telling, however, are important actions and the difference between them is often worth preserving. If you would prefer to make "tell sybil about X" do the same as "ask sybil about X", the following rule would serve:

Games with a lot of conversation often involve great heaps of rules like the ones above, which can be repetitious to type out. We shall also later see (in the chapter on "Tables") that we can tabulate questions and answers in a much more concise way, if we prefer.

WI §7.7. The other four senses

The five senses are all simulated with actions. Sight is so informative that it is handled by a whole range of actions: "looking", which describes the general scene; "examining something", which takes a closer look at a specific thing; "looking under something", and so on.

The other senses have one action each: "listening to something", "touching something", "tasting something" and "smelling something". It makes no sense to touch or taste the general scene, but listening and smelling are a different matter: we often just listen, without listening to anything specific. If the player types the command "listen", Inform understands that as listening to the current location: similarly for the bare command "smell". Thus:

WI §7.8. Rules applying to more than one action

A description can include more than one choice of action. For instance:

matches either of "examining the desk" or "searching the desk". We can have more than two actions, of course:

The actions combined like this need to be compatible with each other, at least a little. For instance, this will generate a problem message:

because it makes no sense to "wait the desk". On the other hand, this is fine:

The general rule is that if we specify one or more objects ("the desk" in the above example), then each of the actions we quote must take at least that many objects.

For example, the following saves us writing the same basic rule three times over:

WI §7.9. All actions and exceptional actions

The special description "doing something" (or "doing anything") matches any action, and "doing something to ..." also allows the noun to be specified.

For instance, the following puts its object out of bounds:

We sometimes need to be a little careful here: "waiting" qualifies as "doing something", but not as "doing something to something", because there is no object. "Putting the handbag on the cucumber sandwich" would also not qualify as "doing something to the cucumber sandwich" - only to the handbag.

More often, we would like to restrict the range of allowable actions to a select few. For instance:

(Or we can write "except" instead of "other than".) Or we might have an object, too:

Note the "with", which is crucial here. Without it, the rule is subtly different:

This second version matches if the action is, say, taking a shield, or even just looking, because that would be an action other than examining the dagger, taking the dagger or dropping the dagger.

WI §7.10. The noun and the second noun

Once we begin applying rules to actions which are not entirely known in advance, we have a problem: there's no way to find out what specifically is happening. Consider the following:

This is fine as far as it goes, but clumsy. What if the player had examined a human being? Then "it" would be inappropriate. A better approach would be this:

The "noun" and, when necessary, the "second noun" are values which can be used in any rule about actions, and it follows that they can also be substituted into text, as this example demonstrates. Results might include:

This seems a good moment to mention that if you use "The" in a substitution, then a capitalised "The" will be used so long as this is grammatically correct (Lady Bracknell, as a proper noun, takes no article); "the" becomes a lower-case "the" along the same lines; and "a" a lower-case indefinite article.

WI §7.11. In rooms and regions

Three elaborations of action descriptions increase the range of possibilities further.

Like the objects to which the action applies, this location - the "in" clause - can take any description, not just an explicit place like "Supernatural Void":

But we often want a rule to apply in any of a set of rooms: and where, unlike the "dead end" example above, the rooms have nothing much in common except where they happen to lie on a map. For instance, we might want a rule to apply only inside a given building, or a garden consisting of five miscellaneous rooms. If so, we can create a "region" as a convenient way to refer to that group of rooms:

WI §7.12. In the presence of, and when

Relative location can also be important: relative to other people, that is -

As might be guessed, this applies when the action takes place in the same location as the person named: and of course that person can also be described more vaguely ("... in the presence of a woman", say), and can just as easily be an inanimate thing ("... in the presence of the radio set").

Lady Bracknell is a pushover compared to some matriarchs:

The last of the optional clauses we can tack on to the description of an action is the most general of all. We can add "when" and then any condition at all, as in:

This supposes that the radio is so loud that it can be heard from any room: we could muffle it so that it's only audible from the room it is in like so:

WI §7.13. Going from, going to

Going is an action defined like any other: it is the one which happens when the player tries to go from one location to another. But it is unlike other actions because it happens in two locations, not just one, and has other complications such as vehicles and doors to contend with. To make it easier to write legible and flexible rules, "going" is allowed to be described in a number of special ways not open to other actions, as demonstrated by the following example story:

Note that "going nowhere" means trying a map connection which is blank, and if no rules intervene then "You can't go that way" is normally printed. Unless "nowhere" is specified, descriptions of going apply only when there is a map connection. So "going from the Musicology Section" would not match if the player were trying to go east from there, since there is no map connection to the east. Similarly, "going somewhere" excludes blank connections.

The places gone "from" or "to" can be specific named regions instead of rooms. This is convenient when there are several different ways into or out of an area of map but a common rule needs to apply to all: so, for example,

Note that it must be "going nowhere from the Wilderness", not "...in the Wilderness". (Note also the caveat that the regions must be named: "going from a region", or something similarly nonspecific, will not work.)

An important point about "going... from" is that, as mentioned in general terms above, it requires that there is actually a map connection that way: whereas "going... in" does not. Suppose there is no map connection north from the Wilderness. Then:

The first of these never happens, because it is logically impossible to go north from the Wilderness: but the second does happen. (Technically, this is because "going north" is the action, and "in the Wilderness" a separate condition tacked onto the rule.) This distinction is often useful - it allows us to write rules which apply only to feasible movements.

This may be a good place to mention a small restriction on the ways we can specify an action for a rule to apply to, and how it can be overcome. The restriction is that the action should only involve constant quantities, so that the following does not work:

because "the location of the rabbit" is a quantity which changes in play (the player can pick up the rabbit and take him to the Dome, for instance). However, we can get around this restriction by defining a suitable adjective, like so:

WI §7.14. Going by, going through, going with

Adding to the previous example story, we apply rules which depend on travelling by a particular vehicle:

And, lastly, rules which apply to movements through particular doors:

(Note that these apply whether the action is "going east" or "entering the green baize door", each having the same effect.) The last rule is worth a second look: the normal way that a "going" action is reported is to produce the room description of the new location. So if an "after" rule stops the action before we get to reporting, we have to produce any room description by hand (hence the "try looking" to cause the looking action). Alternatively, we could simply say something and let the normal course of events take place:

Finally, going is an action which can also happen while the player is pushing something from one room to another, and we can describe this like so:

"Going" is not the only action which moves the player. Another is "exiting", an action which moves the player out of whatever he/she is currently in or on. This action is often caused by the player typing just OUT or GET DOWN, and there's no noun as such. But Inform allows the syntax "exiting from" to make it easier to write rules about the exiting of particular containers or supporters:

WI §7.15. Kinds of action

Especially when people need to react to events going on around them, it is helpful to be able to categorise actions into whole areas of behaviour. For instance:

Here a new kind of action called "unmaidenly behaviour" has been created and then used in the description of an instead rule. The convenience of this approach is that when further actions suddenly occur to us as also being unmaidenly - say, attacking Mr Carr - we only need to add a single line:

And this will automatically be reflected in any rules which concern the consequences of failing to be ladylike.

(Note that we were only allowed to say that "Kissing Mr Carr is unmaidenly behaviour." because Inform already knew from earlier sentences - see the example below - that Mr Carr was a person, and therefore that "kissing Mr Carr" made sense as a description of an action.)

WI §7.16. Repeated actions

We come at last to the final thing which can be specified about an action, and appropriately enough it must be specified with the final words of the description. This is the way to talk about repeated activity:

Note that we are allowed to spell out numbers up to twelve in English words, but beyond that must use digits (thus "twelfth" is allowed but not "thirteenth": "13th" should be used instead). The following example is instructive:

This means that it is the fourth time a "taking..." action has been tried, and does not mean that the same item was taken each time. Also, note that we are counting the number of times the action has been tried, not the number of times it succeeded.

WI §7.17. Actions on consecutive turns

We can also reckon the number of consecutive turns on which an action has been repeated, by talking about "turns" instead of "times", as demonstrated in the following example story. Note also that we are allowed to use the phrase "doing it" to mean "the same description as the previous one except for the part about turns or times", like so:

Note once again that numbers above twelve must not be written out, so "more than twelve times" would be acceptable, but we would write "more than 13 times".

WI §7.18. Postscript on actions

In this chapter, all actions have been carried out by the player, all have been drawn from the standard stock of built-in actions ("unlocking", "taking", "going" and so forth), and all of those built-in actions have been allowed to work in the standard way - we have seen how to prevent the taking of something, and how to give this unexpected consequences, but not how to make taking work in an entirely different way.

All three of those restrictions will later be lifted in the chapter on "Advanced Actions", but otherwise we have covered the ground thoroughly, and it is time to move on to the techniques enabling us to do more than make tart replies to the player: it is time to change the world.