A transparent game's mechanics can be grasped in their entirety. They're not hidden in black boxes, or behind giant formulas. Instead, those games generate challenge via systemic and strategic depth. The following article will try to shed some light on the types of games that would be wise to follow the design guidelines of transparency, and what that actually means.
Of course not all games have to be transparent. Rulesets designed to depict a segment of reality or a specific fantasy typically don't care too much about gameplay clarity. On the contrary, from a traditional design point of view many of them could be called cluttered, vague, and bloated.
Let's look at Dungeons and Dragons for example. Its quite extensive arsenal contains a scimitar that barely differs from the short sword in terms of gameplay. In theory one could very well argue one of the two should either be changed dramatically or removed altogether. However, for those who like playing a pirate captain avatar, having both items is obviously indispensable. After all, the pen-and-paper RPG doesn't care about elegance or focus, but lives by its players creating a story together.
In general, most fantasy simulations are quite open when it comes to their interactivity, sometimes rather chaotic in their results. Dwarf Fortress for example relies on its immense simulative depth. Big-budget productions such as Assassin's Creed or Uncharted on the other hand bank on technological fidelity: Characters made from thousands of polygons move fluently animated through continuous three-dimensional space. They aim their weapons into a plane of infinite points and can pull the trigger at just as many points in time. The spectrum of nuances between all the possible actions is anything but discrete. The overwhelming physical complexity of the real world is simulated inside the game to convey a sense of presence to the player, to believably simulate the fantasy of moving through the game's world.
On the opposite side of the spectrum, there are games that focus on the gameplay itself, independently from their setting. They try to repeatedly present players with interesting decisions and challenges without drowning them in excessive complexity. Narrative elements are used to explain the mechanics much more than for their own sake. The players' experience is shaped by clearly defined options, immediate feedback, and iterative learning. Fundamentally, those titles could be called "designer games", since all the design decisions are made with the gameplay system in mind, and not dictated by the necessities of an accurate simulation.
Transparent games lay their rules open!
At their core, games such as League of Legends, Atlas Reactor, Overwatch, Gwent, or Civilization fascinate their players by allowing them to make plans meant to deal with complex situations. Obviously this can occasionally occur in fantasy simulations as well when they depict inherently strategic conflicts (e.g. war, a sword fight, or the stock market). Most of the time they are not specifically deisgned around those, ultimately incidental, elements of planning.
In any case, formulating a coherent plan is only possible if the game's mechanics are out in the open. Players have to know how the system fundamentally works, and be able to easily process the available information at any point in time, to determine the current game state's meaning. That is why one ingredient in the design of those games is absolutely essential: transparency.
The most fundamental type of transparency concerns the ruleset itself. Players should have access to all the rules at any time. And those rules ideally should not leave any questions unanswered. With board games this is common practice of course, since all steps and bookkeeping have to be manually performed by the players.
However those creating digital designer games would also be well advised to stay transparent in this regard. After all, even if a computer can deal with arbitrarily complex formulas, the player's mind can't. Information can only be factored into making plans if it can be grasped almost immediately. Statements such as "Just let the computer do it!" are not a good argument for going digital, but an indication of a non-transparent, or at the very least borderline complicated, mechanism.
With today's games regularly making use of "expert UI" modes, the fear of overwhelming players with too much or too detailed information should also be a thing of the past.
"Advanced tooltips" provide transparency in Diablo 3.
But not only should players know about all the steps of calculation a game does, all the potential results any action can have, and if need be the probabilities of all those. On top of that, players have to be able to compute and comprehend all of this with ease, basically "on the side". Mere arithmetics should never steal the show from higher-level strategic considerations.
If players have to deal with adding and subtracting numbers constantly, there's little time left for truly deep and interesting decisions. That's why information should, whenever possible, be represented in more intuitive ways. A typical example of this is a tactical grid in turn-based strategy games that represents complex mathematical relations in a very accessible way. And if there are still bare numbers involved, they should ideally be small have a very discrete range, so that a human brain can easily deal with them without having to take any intermediate steps of abstraction first.
Transparent game mechanics allow (and demand) designers to place all the strategic depth directly on the level of systemic relations. After all, the game has to be emergently complex enough to be not trivially solvable, even though all its parts are very transparent when looked at in isolation. Players have to be presented with difficult choices, even though the full systemic context flows into the plans they're making. And precisely because that's the case, those decisions can be very interesting.
Another tool on the path to a transparent game is abstraction. Firstly, it can be employed on the level of the interactivity itself. Many strategy games translate the "real", continuous battlefield into a much clearer tile-based representation. The temporal counterpart is of course converting chaotic but realistic real-time action into turn-based decision-making. So, mechanics can be discretized for the sake of gameplay clarity. If they aren't, preview functions can help to some extent.
Previews can help orient oneself in continuous space.
Visible previews are directly linked to another aspect: audiovisual transparency. Graphics that are very beautiful or realistic in and of themselves as well as atmospherically dense sound effects will often drown stimuli actually relevant to the gameplay in cinematic noise. Again, what may be great for the purpose of fantasy simulation can actually harm designer games at their core. Therefore the latter have to be delibarately abstract in their presentation, at least to a certain degree. As Ryan Scott, lead designer for League of Legends, wrote: "Players should fight their opponents, not the game."
But what if a competitive game does not want to completely abandon the potential excitement stemming from simulative chaos? Actually even in that case not all is lost, as long as the characteristics layed out above are to be found on a metagame level above the core gameplay. Most recently, Playerunknown's Battlegrounds combined comparatively realistic shooter gameplay and an unusually abstract metagame framework, which prescribes exactly where players will have to be at each point in time. On Kotaku, Heather Alexandra called the game's "lack of rules" its biggest strength. It's certainly not. In a way, the core shooter gameplay is simply being used as a big uncertainty factor for an actually pretty strict (and also transparent) metagame.
PUBG: Shooter simulation meets abstract metagame.
The same is true for Rocket League's physics simulation. It's basically impossible to fathom completely, predict perfectly, or factor into a plan flawlessly. Quite in contrast to the overarching "car soccer" ruleset, which can of course be strategized around. However, success will always hinge on physical execution as well. Players can of course practice for it, but looked at from the strategic level, it's an external factor - just like rolling dice to determine damage in many board games.
As accessible, tangible and clear as transparent games should be, as complex and nuanced are the involved characteristics. On top of that, one will most of the time not come across "pure" fantasy simulations or designer games in the wild of the gaming landscape. Instead there are all kinds of hybrids. And as the last-mentioned examples show, some of them can turn out quite bipolar.
In any case having clear priorities when designing is important: If you're creating a simulation to convey a fantasy experience or a real-world snapshot, be careful with abstractions and restrictions for the sake of to gameplay clarity. If you're making a designer game on the other hand and care about making your systems as interesting as possible in the long term, don't give in to the temptations of realism too easily, even though it can seem like the correct and intuitive solution to design problems at first sight. And lastly, if you're trying to put simulative mechanisms into your designer game, make sure you separate the two sides. For example by making use of a transparent metagame.