Analyzing Game Mechanics

What makes a game fun to play?

I have been thinking about games a lot lately--analyzing existing games and playing with my own designs. I am constantly thinking about the above question, as well as its more concrete variation: What makes this game fun to play?

While I certainly don't claim to have solved this problem entirely, I increasingly find myself drawn towards analyzing game mechanics along two critical dimensions, which I've tentatively named: compelling decisions and creative play. I like thinking of these as the beginnings of a more complete framework for thinking about games, like the cognitive dimensions framework for evaluating the usability of notations or programming languages.

It may be the case that these dimension are too broad, and they are certainly incomplete. But I think they provide a nice place to start when trying to understand how a game's mechanics lead to interesting play, or in guiding the development of new mechanics. I should also note that they completely disregard all aspects of theme and the components of a game, both of which can be huge determiners in how a game plays. Finally, this whole exercise may seem obvious to some, but I think that there is some value in stating these things explicitly and considering them in detail.

With all of those caveats out of the way, on to the dimensions. I'll try to use mainstream games as examples, when possible, in the interest of broadness.

Compelling Decisions

A compelling decision is any concrete choice that a player makes which is based on reason, is non-obvious, and has an impact on the outcome of the game. A game with compelling decisions keeps players engaged by forcing them to think, and giving them a sense of control.

Deciding which card to play in a particular trick in Hearts is an example of a compelling decision. In choosing, a player must take many factors into account: which cards they have in their hand, which cards have already been played by other players, whether it would be advantageous to take the lead, etc. This decision is clearly based on reason and impacts the outcome of the game.

An identical argument could be made for choosing which card to play in a trick in Pinochle. However, I would argue that this decision is less compelling in Pinochle than it is in Hearts. In Pinochle there are both fewer different cards and more constraints on which cards can be played and when (for example, you must always beat the best card, if possible). Unless you have the lead, you are frequently choosing from a very small number of cards, and the decision is often obvious. This is not meant as a knock on Pinochle (which has more compelling decisions elsewhere, for example, in the bidding and passing phases), but rather to demonstrate that there are more- and less-compelling decisions, and that perhaps there is a trade-off between constraints and compelling decisions. Clearly, constraints are essential for defining a game, but overly constrained games may suffer from a lack of compelling decisions.

On the complete opposite end of the spectrum, early moves in the paper-and-pencil game Dots and Boxes are not compelling decisions at all, in this case, seemingly due to under-constraint. So it seems the relationship between constraints and compelling decisions is not simply linear, but somehow more complex. This leads to questions like: Can we maximize compelling decisions simply by twiddling the constraints? Is there a single optimal amount of constraint? And, how can we quantify constraints?

Related side note
Games of pure chance completely lack compelling decisions, yet many people still play them--why? Many such games of pure chance are intended for children. Perhaps children are more easily engaged by randomness? Pure chance games intended for adults are often gambling games. Does the excitement of potentially winning or losing money fill the same role that compelling decisions otherwise might?

Creative Play

A game enables or supports creative play if players feel as though they are able to innovate within the constructs of the game. Innovation can come in the form of newly developed strategies, combining game mechanics or making moves in clever or novel ways, or otherwise being able to repeatedly do things which are not obvious upon a first interpretation of the rules. Clearly, this is a somewhat vague concept, more so than the concept of compelling decisions, however, I hope to again clarify with some examples. I should stress that "innovation" on the part of a player does not necessarily mean that they are the first in history to perform some move or strategy. In fact, the designer may have considered or even designed the game with said strategy in mind. The crux is that it feels like innovation to the players.

For my first example of creative play I'm going to go to a hobby game for the first time: Nexus Ops, quickly becoming one of my all-time favorite games. In this light war game you have six different types of units. They always battle in descending order, from strongest to weakest. There are also "Energize" cards which give special abilities, bend the rules, etc. These cards are usually very powerful, but sometimes a card seems underpowered compared to others. One such card, when played, causes a battle to be reversed, and fought from weakest to strongest. At first, the utility of this card seems a bit dubious. But a clever player can use it to great advantage, often in conjunction with other cards which let you teleport weaker units into battle, to topple a group of strong units with a group of weak units. The first time a player uses this card to good effect is both exciting (to the player) and stunning (to the opponent). Clearly, this is a case of a designer building in some propensity for creative play. This is only one of many examples of mechanics with hidden value, or mechanics whose value is only realized in conjunction with other mechanics, in Nexus Ops.

While I'm confident that Nexus Ops won't grow stale for quite some time, it may seem that this sort of built-in creativity may eventually wear itself thin. After all, there are only finitely many combinations of cards and abilities (though that combination is very large). Perhaps Chess can serve as a counter-example. Chess has a seemingly endless supply of creative potential. Thousands (millions?) of people, over hundreds of years, have spent their entire lives playing and studying chess, and still new strategies are constantly being developed. Yet this longevity and variety is achieved with only six different types of pieces and an 8x8 board. Perhaps even more impressive, Go, with one type of piece and even simpler rules, has been studied and enjoyed for literally thousands of years, and still its creative potential has not been exhausted.

In general, I think that games with a significant spatial aspect (like Chess, Go, or war games) may be more amenable to creative play. Also, games with high branching factors (many possibilities at each decision) may also be more likely to have high creative potential.

Among card games, I think that the ladder-climbing games, such as Thirteen, provide great opportunity for creative play. In Thirteen, especially, cards can often be played in many possible configurations. The high number of options, and ability to dictate the cards your opponents must play to beat you, makes playing the lead a fun and often creative exercise. Additionally, deciding when to abandon your original strategy, to break a run by your opponent, is often a highly-compelling decision. This combination of creativity and decision-making (and fast play) makes Thirteen one of my favorite card games.

Final Notes

I think that there is some amount of trade-off between these two dimensions. Creative play is often enabled through open game play, whereas compelling decisions are often created by creating a bottleneck at which a player must make a choice. Exploring exactly where this trade-off occurs may be interesting. Hansa is a good example of a game that offers little opportunity for creativity, but forces one agonizing decision after another (a good thing) by constraining movement and resources. Perhaps this could be contrasted with more open games with similar mechanics (of which, I think there are many).

One question I still have is where "party games" fit into all of this. Can they be evaluated using the same criteria as more strategically oriented games? Perhaps they are generally low on compelling decisions, but very high on creative play?

In future posts I hope to analyze/review existing games. I will probably refer back to this post, but I will almost certainly also allude to aspects, such as theme and the integration of theme and mechanics, which I think are important to games, but which may be of a more subjective nature than the success of the raw mechanics (also highly subjective, I realize). Perhaps at some point I will add dimensions to cope with these aspects of games as well. Or perhaps not--this took a long time that I should be spending on other pursuits (i.e. papers).