Effective design decisions in The Mary Jane of Tomorrow.

Emily Short’s newest game is remarkable in several ways, and I wanted to talk about a few of its features that stood out to me. This essay doesn’t go into the background if the game. It also contains huge spoilers.

=====Accretive puzzle design====

When Hadean Lands came out, many people praised it for the gradual change in scale of the puzzle solving from the small to the large. Mary Jane achieves this same effect, which is remarkable given the relatively shorter time frame of the game. You begin with trying to find any actions that work at all, until the robot reads one book. You then enter a phase of experimentation, where you try to find patterns in the books’ effects, their relationship to each other. Once you understand the rules of the game, you begin to search for new books and conversation options that you know have to exist even though you haven’t seen them. Finally, you enter a meta-puzzle of taking all the books you know and arranging their use to counteract and supplement each other.

This game forces you to see the whole picture at once, with interlocking pieces, like Varicella or Hadean Lands or Rematch.

====Procedural Generation====

Mary Jane represents an immense achievement in procedural generation. The different training aspects of the robot interact with each other and a large corpus (a database with tags) to produce astounding results.

The clever part here is that each aspect can act individually, producing a huge number of possible results. Cowboy culture can modify every other variable by changing spellings and so on. Politeness can change tone. Snobbiness can change the fanciness of words chosen. Advertising or botany can change the level of confidence and knowledge in different areas. And most of these can act at the same time, on different axes. This has produced results that seem almost alive, surprising even the author with some of its creations.

This game is very large due to its corpus, and the benefits are apparent.

====Feedback and user experience====

The last effective decision is the part of a game that is seen less the better the game is: user experience. Many people struggle with parser games, especially puzzle games like this. You can give explicit tutorials, or give gentle in game feedback. Short focuses on the second.

I discovered the robot could read because they told me after a few times. Calling Jenny felt natural, and when I did call her, it made sense to ask her about her requirements. When I tried completing the game too early, it told me in vague terms that Jenny was disappointed, but it was enough to guess what I had done wrong. In every area, there were gentle nudges towards the goals, but the game was still very challenging.

Like Hadean Lands, Lime Erogot, or Midnight Swordfight, Mary Jane removes everything tedious about a game, all of the unnecessary padding, and allows the player to focus completely on the new mechanics.


Mary Jane is a major technical advancement and an excellent example of a how to polish a game. It pushes the boundaries of the parser forward, and it sets a new bar for procedurally generated content in interactive fiction.

Thanks for writing this – I’m glad you liked it!

The core puzzle is formally equivalent to one of those light switch puzzles where one switch turns on lights 1, 3, and 4, another switch turns 3 off and 2 on, and so on. And I’ve always tended to dislike those puzzles for their arbitrariness and trial-and-error nature. The design here tries to alleviate both through fiction: the type of book gives you some clues about which states are likely to be switched on/off, and there’s a fictional purpose other than “light all of these up because I say so” to the project.

Just a random opinion: but Jenny’s attitude whenever I lost was a turn off for me. I mean I am giving her a robot and I’ve put all this work into it (and it felt like I had) and she flips out over it wearing a sash instead of being naked, or because it speaks French? I could understand her being disappointed that I couldn’t make the robot live up to her expectations but instead she just comes off as ungrateful and that my apparently unique and special present doesn’t meet her standards.

I also had a few parser problems: addressing the robot before it was renamed (it wouldn’t accept the whole name, and it actually wasn’t clear to me from the look description that it was robot Jenny/Mary Jane, it was Queen Nutbush or something which I still don’t understand in the context of the game), finding what to call the long book titles to avoid typing them in full. I also didn’t like that their were no responses to trying to call the librarian beyond being told that my character only knows Jenny’s number, I mean I have the flyer and yet it seems only the robot can call the number, doesn’t the flyer have it? If not how does it know the number?

As a newbie player (and intending to stay that way) I was thrown by giving items and having them stay in my inventory without explanation.

I didn’t persist long enough to make the robot Jenny lose her interest in pine nuts, likely because I didn’t manage to understand the logic behind forgetting.