Game Design Glossary

I use a number of shorthand terms in my reviews to describe complex concepts. Some of these are coined by me; others are ones I encountered elsewhere and found useful.

Elements of Difficulty

Difficulty in games is often spoken of as if it’s a single-dimensional value, but in practice it’s made up of several distinct parts. Here are some that interrelate but are worth considering separately:

Challenge is the degree of mastery required of the player in order to complete a goal. It’s the peak skill level needed to perform the correct actions or make the correct choices to prevail.

Strictness is how consistent the player’s performance must be and few mistakes they can make to still complete the goal. This is inversely related to the Competence Zone, which is the space between just barely completing the goal and perfect, flawless execution. Lower strictness means a larger competence zone, while higher strictness means a smaller one.

Punishment is what happens when the player fails to complete a goal. Higher punishment (taking more resources, sending the player further back) generally means it will take longer to get back to the state they were in before failing.

For example, suppose you are playing a Mega Man game where you make your way through a level and then fight a boss at the end. Whether the boss stays more or less still or moves around a lot determines how good the player has to be to hit them with attacks and thus affects challenge. How much of the player’s health is taken by the boss’s attacks determines the number of times the player can screw up and get hit themselves and thus affects strictness. Whether the player is allowed to retry immediately on failure or must get through the level again determines how bad it is to lose and thus affects punishment. All of these things affect the overall difficulty of the boss fight, but they do so in different ways with different implications.

It is Docprof’s considered opinion that in general games should provide a wide variety of challenge levels to suit players of different abilities, minimize strictness to encourage flow states, and minimize punishment to encourage learning.

For more on these concepts, see these Pixel Poppers blog posts:

Phases of Challenge

Challenge in games often has multiple different phases that funnel into each other.

Preparation is getting ready to deal with challenges. Players can improve their own skills via research or practice, while in-game preparation is about acquiring new options or improving existing ones.

Strategy is defining a framework for handling challenges. It includes coming up with plans and choosing a loadout of options that will be usable when dealing with a challenge.

Tactics is making choices in response to specific situations. It requires awareness of the current game state and a decision of which option in the current loadout to apply in the current situation to advance the current plan.

Action is communicating the choice back into the game to update the game state.

Different games, and indeed different challenges within a single game, can vary in their challenge profile - their distribution of difficulty across the phases.

For a much more in-depth look at these concepts, see this Pixel Poppers blog post:

Progressive and Regressive Difficulty

A game with Progressive Difficulty becomes harder as the player’s performance improves. For example, the A.I. Director from Left 4 Dead will give the players more ammo and health pickups if they are doing poorly and will spawn more challenging enemies if they are doing well. This is more accommodating of varying skill levels, but makes it harder for players to feel the results of improving their skills.

A game with Regressive Difficulty becomes easier as the player’s performance improves. For example, in Metroid games a player skilled enough to find the hidden and difficult-to-reach powerups will be better equipped to survive the game’s combat. This rewards increases in skill, but can mean the game is too hard until suddenly it is too easy.

Different players will have different reactions to and preferences between such difficulty schemes. Personally, Docprof dislikes regressive difficulty because it means the process of learning a game is made more frustrating and the reward for putting up with the frustration is a game that no longer provides as interesting a challenge.

For more on this concept, see this blog post by Christopher Gile:

Instructional Scaffolding

Instructional scaffolding is an educational technique in which the learner is given support in the early stages of acquiring new skills or knowledge which is gradually reduced as the learner becomes proficient and independent.

In game design, this generally means introducing new mechanics or interactions in safe situations with strong initial guidance. The player demonstrates basic understanding by completing simple challenges, and is then tasked with applying what they’ve learned in more complex, higher-risk, and less guided challenges.

Properly done, this can smooth out difficulty curves and make challenges feel more fair. Portal is often held up as an example of a game that makes excellent use of instructional scaffolding, teaching the player to “think with portals” and solve increasingly difficult puzzles while making sure all the rules are well understood.

Option Restriction

Option restriction is when a game passively forces the player to proceed in a specific way by removing all other options. The player still decides when and sometimes how to perform the required action, but has no other recourse aside from not moving forward or quitting the game entirely.

For more on this concept, see this Pixel Poppers blog post:

Bad Good Game

A Bad Good Game is good at the core, but is bad overall. The game’s foundation is solid, but surface-level flaws get in the way of what should be fun about it. It could have been a good game if the developers had just a bit more time, money, vision, or freedom from meddling.

For more on this concept (and its complement, the Good Bad Game), see this Pixel Poppers blog post:

Good Bad Game

A Good Bad Game is bad at the core, but is good overall. The game’s foundation is weak, but the deep-running flaws don’t get in the way of what’s fun about it. It could have been a bad game, but there is something about it that rescues it.

For more on this concept (and its complement, the Bad Good Game), see this Pixel Poppers blog post:

Incoherent Design

A game’s design is coherent to the degree that its systems and mechanics work together. If one mechanic encourages a certain player behavior while another mechanic discourages it, that’s incoherent design.

For example, in Akiba's Trip: Undead & Undressed the player has the option to have one of their friends accompany them and fight by their side. Each friend has unique dialog and a powerful team attack, which encourages you to use this feature. But they will often attack enemies in ways that disrupt any chain attacks the player is setting up and sometimes prevent the player from getting unique drops, which discourages you from using the feature. This is incoherent design.

For more on this concept, see this blog post by James Margaris:

Fake Altruism

Many games provide opportunities for players to help each other out. Sometimes, as in Clicker Heroes, this is through a limited and asynchronous form of multiplayer. Other times, such as in World of Warcraft, it’s a core part of the game and is practically required in order to progress.

This taps into our natural and laudable altruistic desires, but it is fake altruism since you’re really only helping people progress in a game. In subscription- or microtransaction-based games, it is often used in an exploitative way to create social obligations of reciprocity and make you feel like a bad person if you stop playing (and therefore, stop paying for the game).

For more on this concept, see these Pixel Poppers blog posts:


Note: In the West, the term “loot box” has come to mean essentially the same thing, though this generally implies a slightly different implementation.

Derived from “gashapon,” the Japanese term for capsule toy machines, gacha refers to a class of game mechanic wherein the player invests a resource to get a reward. While the set of possible rewards is often known, the specific reward given is random, so it can take a lot of time and resources to get a particular desired reward. In some games, such as the Danganronpa games and many Senran Kagura games, the resource is an in-game currency. In others, it’s a premium or real-world currency - this is a very popular method for monetizing free-to-play games.

Docprof generally considers it a bad sign when gacha shows up in a game. Even if it’s not tied to real money, it heralds a lot of wasted time grinding for the resource and playing the machine. When it is tied to real money, it’s a sign that the game has been designed not to provide the best possible experience but to extract the most possible money. Similar to slot machines, gacha exploits the human vulnerability to variable ratio reward schedules - except that because the rewards aren’t money but distinct objects, the new player is rewarded more frequently since they are more likely to get something new.

Sometimes, in addition to the reward itself being randomly selected it comes with a random perk or quality level. This is known as double-RNG gacha because there are two random numbers being generated. They combine for an exponential number of possible rewards, making it that much less likely you’ll get what you actually want (especially as lower-quality rewards tend to be more common).

For more on this concept, see this article by Kirk Hamilton:

Internet Scavenger Hunt

This is my silly term for this because I haven’t heard another one - please let me know if you have!

Some games have puzzles or secrets that are so hidden or obscure that no single player could reasonably solve or find them. The purpose of such content seems unlikely to be to improve the in-game experience of individual players but rather to encourage the game’s fan community to come together and crowd-source the solutions in a sort of internet scavenger hunt. It can be thought of as an evolution of ARG marketing campaigns like I Love Bees that move their content into the game itself.

While it seems like a reasonable way to generate buzz for a game, and the people who work together to solve the puzzles or find the secrets presumably enjoy themselves, Docprof generally thinks this is a bad idea. There are some games (such as FEZ) where content that is specifically designed to be painstakingly deciphered fits in well, but in most games it diverges from the game’s normal difficulty curve and even when solved adds little to the experience. It’s obtrusive for the player who wants their game to be a solitary or immersive experience, and even the player who would like to join the community but didn’t pick the game up at launch has probably missed their opportunity to do so. Both such players will search the internet for whatever has them stumped and be immediately presented with the solution. “How in the world was I meant to know that?” the first player will think, annoyed at this waste of their time with an unnecessary step in puzzle-solving, while the second player will think, “It sure would have been nice to have been able to help figure that out,” and still have their time wasted with an uninteresting step in puzzle-solving.

In short, it gives some enjoyment to a limited group of players for a limited window of time, and then permanently damages the game for everyone.