Quantum Detective: Deadline and the Many Worlds Interpretation

A look at Deadline‘s gameplay: forging one true playthrough out of many failed attempts.

Warning: the story and puzzles of Deadline are spoiled below. If you wish to experience these things for yourself, stop reading now.

Deadline, Parallel Worlds, and Player Omniscience

Up-close drawing of the living room in Deadline. The armrest of a couch can be seen beside an end table. On the table are a black rotary phone and a hardcover book titled "Deadline."
Detail from Living Room as imagined in the Zork Users Group Invisiclues booklet for Deadline. Retrieved from MoCAGH.

In many games, interactive fiction or otherwise, death is common. The player makes a fatal error–or a series of errors–that ends the game in a failure state. Typically, the player learns something from the experience, works their way to the previous point of failure and hopefully prevails. If not, then there is still the hope that they fail in a new way, again learning from the experience. This cycle of improvement occurs across genres and modes of play.

From a narrative perspective, features like saved games usually fall outside of the logic of the game world. So far as the story of Zork I goes, the Adventurer never loads a saved game, just as they never decide to see the world in a “verbose” way. These are player actions, not those of the protagonist. But what of the protagonist in each of these botched attempts at play? They have stories, too. We just don’t follow them through to the end.

For instance: whatever became of the Adventurer who killed the thief before solving the problem of the egg? Did he eventually give up and go home? There are many such unfortunates: the Adventurer who lit the candles with the torch, or the one who tried to wield the rusty knife. How about the one who let the lamp burn out before solving the coal mine? The many worlds interpretation (which I can only explain in simplest terms) suggests that each choice made by the player spawns a universe. There is the universe in which the Adventurer eats the garlic, and one in which he does not. In this simulated multiverse, the player can travel from world to world by restoring a game or restarting a playthrough.

In Zork I and Zork II, the need for this sort of interdimensional travel is relatively light. Most decisions in these games are not monumental if we ignore the pressures of finite light sources. It does not matter, for instance, whether the Adventurer solves the dam puzzle or exorcises the evil spirits first. While the games have a deadly reputation, in truth there are not many ways to die.

From a gameplay perspective, the most important thing setting Deadline apart from the Zork games is its implementation of time. In Zork, the world is acted upon by the player. It reacts to player input. No matter how many turns the Adventurer waits, it is impossible to miss content. The troll does not tire and go to sleep. The vampire bat is ready whenever you are. The thief does not punch the clock and head home for the evening. Deadline, by contrast, keeps its own schedule. Things happen and characters do things whether you are there to see them or not. Sucess in Deadline may or may not require a traditional 2D map, but it will likely consider a bit of chronological mapping.

Brief explanation of the Many Worlds Interpretation

It’s fitting to think about this new requirement in terms of quantum mechanics. Unlike Zork, where many sorts of failure can be avoided without contending with waveform collapse, Deadline requires–by design–many deliberately failed investigations. When these gameplay choices are compounded by the constant possibility that the player is missing out on something happening somewhere and/or somewhen else, travel between universes becomes a primary gameplay mechanic.

As only one example: the player is suspicious of George. In order to get an understanding of his actions throughout the day, the Supervisor will watch him for the entire twelve hours of play. He will follow George around, sometimes watching from a distance. While the Supervisor is doing this, he will likely miss out on certain events elsewhere. The Supervisor will have no compelling evidence or theory of the crime to show for his efforts, just a timeline of George’s activities. This playthrough, in other words, ends in a failed state. That protagonist may wind up in trouble at work, who knows? The player leaves him to his fate and starts another playthrough, this time armed with a full account of George’s day. This time, the player may decide to explore the grounds. They will likely learn something at the expense of missing events inside the house.

By the end, the story of Deadline will be built atop the empty husks of fail states, the clock ticking forward in parallel with an uncountable number worlds spawned by different player choices. This player, capable of a sort of virtualized omniscience, knows of them all. In other words, the player has knowledge of each new universe spawned by their choices, and will, in time, synthesize their knowledge of this multiverse to craft a canonical playthrough in which the killers are brought to justice. Unlike the Zork games, Deadline asks its player to deliberately fail not once but many times.

An attempt to illustrate the paradox of Schrodinger's cat. A film strip featuring a cat, a skull and crossbones, and an atomic symbol occupy one frame of a filmstrip. The film strips into two branches. The first branch shows the cat alive which the second depicts it as dead.
Visualization of Schrodinger’s cat. Art by Christian Schirm.

The setup may remind one of the paradox of Schrodinger’s cat. A cat is sealed in a box with a deadly trap of some kind. Until the box is opened, there is no way of knowing whether the cat is alive or dead. In quantum terms, the cat is BOTH alive AND dead until its state can be observed (i.e., the box is opened). The many worlds interpretation offers a solution to the paradox: the alive/dead possibility spawns two universes. In one, the cat lives, and in the other it dies. The implementation of linear time in Deadline combined with unknowable states (what has George been up to in the library?) posits a multiverse that is both simple (the canon playthrough) and infinitely complex. The successful player of Deadline must manipulate these states in a way that a player of Zork need not.

Deadline‘s Innovations: Investigative Techniques

Marc Blank’s implementation of linear time is not the only novel feature of Deadline. The game is also, for its time, unusually complex when it comes to conversation with NPCs. For the first time in an Infocom game, the player can ASK X ABOUT Y:

>ask mrs robner about george
"A child. He may be a man in age, but he still hasn't really grown up. He'll find himself someday, but in the meantime he can be a trial. I guess Marshall and I were too lenient. We probably still are, but he is our son, after all. We can't throw him out on the street."

Additionally, the player can SHOW objects to characters and get a reaction:

>show stack to baxter
He reads slowly and leafs through the pages. "I'm afraid I haven't been entirely candid with you. There was some trouble a few years ago with Focus Corp. because of some, let us say, irresponsible dealings on my part. Marshall agreed to cover up my involvement to save the company any bad publicity."

Character answers can also change based on in-game events. I feel that this all would have been quite novel in 1982. I can tell you that after many failed attempts to converse with the demon and the wizard in Zork II that it was certainly new to Infocom. Additionally, the simulated spacetime of Deadline allows for additional, nonverbal interactions. As suggested above, the Supervisor can surreptitiously follow a suspect in hopes of catching them in a suspicious act:

East Lawn
You are on a neatly manicured lawn, east of the house, which extends north and east to the shore of a lake. To the northwest is a peaceful orchard, and toward the south another wide lawn. Southeast, beside the lake, is a small shed with a solitary dirty window.

>look in window
Mr. Baxter seems furious and about to strike Ms. Dunbar, then calms himself. Ms. Dunbar starts to cry and is embraced by Mr. Baxter.

These interactions all fall under the general heading of “cool detective stuff.” Elsewhere, the Supervisor can HIDE (an in-game verb) and lie in wait, COUNT (after two games, the verb is finally good for something) teacups, snoop in peoples’ medicine cabinets, and compare a ladder’s base to holes in damp soil.

The Supervisor also has access to a crime lab. The ever-helpful Seargent Duffy can take objects to the lab to be ANALIZEd or FINGERPRINTed. These efforts take in-game time, so the wrong choices will tie up the lab until the testing is complete.

As always, these player actions are choices that spawn parallel worlds that hopefully push the Supervisor to a canon playthrough.

A Note on Difficulty and Fairness

Deadline is notoriously difficult, and often discussions of its difficulty drift into assertions of unfairness. At one point, there is a need to SEARCH NEAR a pair of holes (that match the ladder) in the rose garden. It is commonly argued that this action is unmotivated–why would anyone SEARCH NEAR something?

Much attention has been paid to Infocom’s use of feelies for copy protection, but I rarely see the actual game manual cited. We seasoned players would likely never read the manual today. We know how these games work, after all. As it turns out, this is a mistake. In many Infocom titles post-Zork, game-specific commands are essential to completing titles like Deadline. An 80s player would be far more likely to read the manual to discover, in plain view, an entry for SEARCH NEAR.

An image of the "Search Near" command in Deadline's player manual. It reads: "SEARCH NEAR (something). Looks closely at the area immediate to something, possibility providing more information than simply examining it.
Detail from Deadline manual, folio edition. Retrieved from MoCAGH.

A player at the time would, in all likelihood, be actively looking for a situation in which this command would be useful, while a contemporary player might not. I recall having no difficulty with this particular situation in the 1980s.

The puzzle of George and the locked safe, on the other hand, proved blisteringly difficult for me. Since George is the only character with an apparent motive, a player might not realize that there is something other than the will inside the safe. For the longest time, I felt such a sense of accomplishment finding the will that I did not think to look for more. I think this problem is nevertheless fair: the room description clearly points out whether the safe is open or closed.

Still, the hardest part of Deadline is accepting the need for a Many Worlds approach. In general, contemporary players have little patience for “zombie” (unwinnable) games. Expecting a player to deliberately play through multiple dead games violates several of Nelson’s “A Player’s Bill of Rights” and is out of step with current craft theory.

Still, it can be enjoyable to return to such a lawless frontier. A willingness to accept Deadline as it is positions the player as Quantum Detective and creator of a multiverse which–enjoyable or not–at least sounds pretty cool.

Next: A Final Assessment of Deadline in Cultural and Historical Terms

A close up of a partial map of Deadline's locations.
Detail from early version of Zork Users Group map for Deadline. Retrieved from MoCAGH.

12 thoughts on “Quantum Detective: Deadline and the Many Worlds Interpretation

  1. > The successful player of Deadline must manipulate these states in a way that a player of Zork need not.

    This may be notionally accurate but in practice the opposite is true. Zork is entirely designed around the many-worlds approach, which it inherited from Colossal Cave. There is no way to solve Zork without many, many rounds of learning by failure. (Unless you play from a walkthrough — but that is true of Deadline as well.)

    You say there aren’t that many ways to die in Zork. This is arguable. (The source contains 29 calls to JIGS-UP, the death function.) (I had entirely forgotten that you can suffocate yourself by brushing your teeth with the gunk!) But, my point is, there are many *many* ways to fail. Critical resources can be squandered, used up in the wrong place, or ruined by bad luck. The light-source limits and the Thief’s pilfering are only the most remarked-on examples. There is absolutely no guarantee that innocent exploration or experimentation won’t leave you stuck in a zombie state.

    Thus, the experience of solving Zork amounts to marshalling the lessons of innumerable failures into a careful plan for success. To players of the era (me), Deadline felt entirely familiar in that aspect.

    The many-worlds idea was a core axiom for Infocom; they never seriously reconsidered it, even in “introductory” adventures like Wishbringer. It wasn’t until the post-Infocom period (Loom, Myst) that designers really got to grips with the idea of “unlosable” or (my term) “merciful” game design.

  2. To begin: I never came across the gunk suffocation. It is thrilling to continue to learn about Zork after all these years.

    I may have trivialized the many ways to fail in Infocom games. What I hoped to get at was the spirit in which these failures occur. Learning via a failed game is common in almost every Infocom game (should AMFV be excluded?).

    Still, I thought Deadline was distinct. Due to the nature of linear time, all locations apart from the Supervisor’s occupied room at the moment of occupation are in an ambiguous state. IE, some event could be occurring in each of these places and times. The only way to resolve the ambiguity is to spend time that is likely to be unproductive in one worldline while informing a player’s limited omniscience.

    As a consequence, the player must deliberately make decisions that lead to failure for Supervisor 1 (S2, S3, etc.). I think this is a different experience from “I took my lamp into the lake with me.” As an example from my own playthrough, I did a stakeout outdoors to see what would happen. Spent the whole day out there and figured out I could find the holes before the reading of the will. It was never intended to be a winnable game, and I think this is exclusively a Deadline phenomenon. The Zork player does not hang out in the Coal Mine to see if something will happen at turn 200 because that is not the nature of Zork.

    I was a player of the era, too. It took me years to solve Deadline. Probably a record for me in terms of time spent, but it really was hard. It is also one of my favorites; I think I may be an outlier in that regard.

    Many of the deaths in Zork are jokes, aren’t they? Does BRUSH have a function beyond the gunk death? Maybe I should bumble around in the source and count “serious” (or productive, hint-wise) deaths. I always see the egg mentioned as the cruelest source of zombification. I’d probably enjoy chasing the count of zombification causes, too.

    So. I think it was a mistake to minimize the cruelty of Zork, but I think Deadline is unique in using zombification as a strategy (at the time, anyway, these things come up in later mysteries).

  3. “As a consequence, the player must deliberately make decisions that lead to failure for Supervisor 1 (S2, S3, etc.).”

    I think that, right there, you have nailed the distinction. You never deliberately fail in a Zork; but you do that all the time in Deadline.

    There is another nice example of hidden copy-protection in Sorcerer. The infotater, which is used for some obvious colour-code copy-protection early in the game, also mentions that the Yipple is “Master of disguise, able to change form. In the wild, may bite if disturbed. Violently allergic to many kinds of animal wastes”. Having read this, when I looked in the barrel of the cannon at the fort, and saw lots of identical scrolls, I was able to realise they were Yipples replicating one real scroll, and to immediately see what the solution is — an action that would otherwise be unmotivated. I like this. It’s elegant.

    1. Mike, I apologize for this late reply. Your comment was somehow flagged as spam! I’m glad that came across. In nearly all games I hope my current playthrough will be my best and final run. In order to succeed in Deadline, I had to think differently.

      I enjoyed the yipple puzzle quite a bit. I think the best sorts of copy protection can be tied to in-universe lore–they can expand our understanding of the game world. The Infotater also helped me achieve an appropriate level of freak out when the dornbeast appeared in the maze!

  4. re: the mention of SEARCH NEAR in the manual, when I played I did try to recreate the original experience to the best of my abilities, so I did read the manual carefully and saw the piece about SEARCH NEAR just as you guessed someone might do. There are an enormous number of new verbs and even searching things by themselves (without the extra syntax) would essentially be novel at this time. I wasn’t sure until I read if Duffy was a thing yet, and certainly didn’t know about the syntax about analyzing for a specific substance until I saw it mentioned.

  5. I have Folio of Deadline. It definitely requires this style of gameplay. So does The Witness (I also have the Folio). The most frustrating thing about both games was when I’d figured out the murder, via these alternate-timeline stakeouts, but couldn’t figure out the correct sequence of actions to *prove* it.

    I think this is one of the most frustrating things about the multiple-worlds approach where you run deliberate test scenarios. If there’s an additional layer of puzzles coming from “I know this is true from a different run-through, but it’s nonobvious how to prove it in a winning runthrough” that can just be too much. I’d love to play a game in this style again where the translation from “saw this during a stakeout” to “found evidence for it in the winning run” wasn’t so excruciatingly difficult as in Deadline and Wtiness.

  6. Because I didn’t originally have a bought copy of Deadline, I totally missed the mention of SEARCH NEAR in the manual. Likewise, in Suspended, there is an unusual command mentioned in the package documentation that is utterly essential for victory.

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