A Game Design Grammar

What does it mean to talk of a grammar of game design? And does specifying such a grammar give us an insight into the underlying structure of games, or a new method for approaching game design - or both? Because games vary from pure mathematical formalisms (at the ludic extreme) to behavioural descriptions (at the opposite extreme), any formal reductionistic system will either be focused primarily on the former, or require sufficient latitude to express practically infinite diversity. One such approach is to define a categorial grammar of game design.

My postgraduate degree project, over a decade ago now, was to teach a computer to read, - specifically, to teach a computer to read Ladybird Early Learning books... you know the kind of thing. 'Jane'. 'The Ball'. 'Jane kicks the ball'. The method used was called categorial grammar; a form of context-free grammar similar to lambda calculus. A brief introduction can be found here. In essence:

• S denotes a complete Sentence
• Sentences are composed of Noun Phrases (Jon, My beautiful wife, The queen of Sheba) and Verb Phrases  (works for the government,  married me for some strange reason, is just passing by). Verb Phrases are everything you have to add to a Noun Phrase to make a Sentence
• NP denotes a Noun Phrase
• S/NP denotes a Verb Phrase - which is to say, divide S by NP and you get all the remaining elements
• The grammar operates like fractions in mathematics - for example: NP x S/NP = S (the NP's cancel out to leave S=S, which is correct).

All very well, you are thinking, but what does this have to do with game design? For many years now, I have made card games and boardgames along grammatical principles - mostly subconsciously, although more recently in a conscious fashion.

In essence, any game consists of Nouns and Verbs. For example:

• In Snakes & Ladders (Chutes and Ladders in the US - what's the matter with the US; are they afraid of snakes?) the Nouns are the Counters, the Board, Ladders, Snakes and the Die. The Verbs are Roll (the Die), Move (Counters along the Board), Climb (a Ladder) and Slide (down a Snake).
• In Magic: The Gathering the Nouns are Permanents (Creatures, Enchantments, Artifacts and Land) and Instants/Sorceries and the Verbs are Lay (a Permanent), Tap (a Permanent), Attack and Play (an Instant/Sorcery). There are two additional Nouns - Mana and Life - which are Count Nouns (Resources).
• In an arbitrary basic racing video game, the Nouns are Cars and Courses, the Verbs are Steer (a car), Accelerate (a car) and Brake (a car).
• In the game of Sink (played by Discordians, and people of much ilk) the Nouns are The Float, the water, and the Junk. The Verb is Throw (the Float into the water or the Junk at the Float).
• In a tabletop RPG (in a general case), the Nouns are infinite and the Verbs are infinite. I knew there was a reason I used to enjoy playing them!

My categorial grammar of game design, therefore consists of the following terms:

• G denotes a Game
• N denotes a Noun, and [N] denotes a collection of Nouns
• V denotes a Verb, and [V] denotes a collection of Verbs
• [N] x [V] = G

(This is different from the purely formal structure of categorial grammar of language, but I hope it is apparent that it is inspired by similar principles).

In terms of analysing games, the advantage of this model (and it is only a model) is that it focuses on the game objects (the Nouns) and the player actions (the Verbs, although in a video game we have an extra player - the Computer - who may have their own set of Verbs). Notice that it does not express elements that some people would consider essential to a game - such as a goal state. I consider this quite healthy. The most interesting thing about a game is its play, not its goal - and indeed, when game design is focused purely on the player's goal (as it is in many shoddy video game designs) the result is usually an abysmal wreck.

In terms of running the grammar in reverse, this approach allows a game to be judiciously constructed from components - although wisdom and intelligence are of course needed to do this effectively. For instance, if we want to make a card game, we know one of our Nouns is (a) Card, and that all or most of the other Nouns will be comprised of multiple cards - these Nouns will often include a Deck, Hands and a Discard Pile. From there, we just need to consider the actions the player can take - the Verbs of the game.

As an example of a card game that was designed on these principles, consider the game of Underwear. This remains one of my favourite card games, as it is simple to learn, contains enough luck for any player to feel they always have a chance to win, and enough strategy for players to feel their decisions affect the outcome (especially in head-up play, which can be quite viciously agonistic!)

When we are dealing with games more complicated than card games (and I advocate all new game designers should begin by learning to make card games) we need to add a few new categories to our grammar. What we need is to define the properties of Nouns (and potentially of Verbs) - that is, we need Adjectives (or Adverbs). Adjectives are N/N and Adverbs are V/V, which is to say they cancel themselves out in grammatical terms - an Adjective takes a Noun and returns a (modified) Noun.

Examples of Adjectives in games:

• In Snakes and Ladders and in Sink there are no Adjectives.
• In Magic: The Gathering, the Adjectives include Tap Effect, Power, Toughness, Counters, and Casting Cost.
• In an arbitrary basic racing game, the Adjectives include Top Speed, Acceleration and Traction (Super Sprint, anyone?)
• In a tabletop RPG, the Adjectives describe the mechanics of the game; Attributes, Skills etc.

Although I have been using grammatical game design principles for many years now, it is only very recently that it occurred to me to employ them in video game design. The inspiration for doing so was listening to Toru Iwatani and Keita Takahashi talk about game design - they were focused on verbs, because verbs describe what the player actually does.  (As Ernest is fond of saying: "Yes, but what does the player actually do?"). This lead in turn to the "Verb games" that I have been designing recently, the first of which is Fireball.

The "Verb games" are all built upon the methods expressed in categorial grammar of game design - they consist of a dozen or fewer Nouns and around two Verbs. Adjectives are kept atomic - one per Noun, usually. I believe applying this approach to video games has created games with a particular feel, despite the games themselves being surprisingly different. It's been an illuminating and absorbing adventure, but it's only just begun. The real adventure with Fireball is what complete strangers are going to make using the tools!

We cannot have too many methods for approaching game design, and it is in this spirit (diversity, again - a common theme for me) that I present this categorial grammar of game design. Perhaps you won't find the system useful, in which case all that has been lost is the time to read this post. Perhaps you will be able to use the system to explore new ways of designing games, in which case it was well worth the time I spent typing it out.

In the unlikely event it catches on, let's not turn it into an ugly acronym (CGoGD); how about something whimsical like Cat Design? Well, I'll not spend too much time naming it - one cannot control language - it always finds its own way.

Have fun!

Comments

[Patrick Dugan]

This is good, good stuff, at least in the capacity of making design documents much easier to read and write. IMO Verbs are the most important, with Adverbs, the dynamics of verb execution, being the second most important, and then nouns and adjectives coming in last. But what about prepositions? My hunch is they'd have something to do with fuzzy constrain propagation in adaptive games, but thats a whole other layer of the atmosphere.

I probably don't have to tell you that much of the industry's current trouble stems from a decades long obsession with data-driven nouns.

[Patrick Dugan]

A recent post of mine addresses verb management with analogy to physics, particularily for interactive storyworlds which hundreds of verbs, instead of two.
If anyone's interested:

http://kingludic.blogspot.com/2005/11/verb-oscillation.html

[Chris]

I'm wary of extending metaphors too far... For instance, I don't believe there's a way to make tense (past, future, present etc.) extend to the game grammar - but then, we simply don't need to do that. Although I've termed it as a grammar, it's really a hybrid between a linguistic grammar and a mathematical grammar.

I read your post, which is a delicious explosion of ideas. I particular like the observation that game verbs operate on different scales - there are the immediate verbs (microVerbs) that define player action and also the framing verbs (macroVerbs) which define short, medium and long term goals. I hadn't considered this before.

[zenBen]

"In the unlikely event it catches on, let's not turn it into an ugly acronym (CGoGD)"

How about just GoD - Grammar of Design? Or Cat GoD?

[Bezman]

I feel like I've been shifting towards this type of thinking recently and having it formalised provides a more concrete way to go about examining a game whilst developing it.

Having said that, how dare you give us all these spoilers in the 'game' of developing this line of thought. You could have had a spoiler warning!

I feel we should be fake enemies. If it helps, I'll pretend to hate squirrels.

Also, despite your desires, I shall call it 'grammar-based design' as that seems simple enough to say, whilst explaining concisely what it is to anyone unaware.

[Chris]

Bezman: glad this is useful to you! I found this tremendously valuable a few years ago (see also the piece on structural specification, which connects with this) but these days my head is in a different space. I think I'm wrestling with a different set of problems, to some extent.

"Grammar-based design" is fair enough, I suppose, as far as names go.

Fake enemies? Then it is to be Fake War between us! ;)

Best wishes!

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All very well, you are thinking, but what does this have to do with game design?