What a mechanic is
A game mechanic is a rule or system that defines what you can do and what happens when you do it. Jumping is a mechanic. So are collecting coins, taking damage and spending money to upgrade a weapon. Mechanics are the parts; the way they combine into a playable whole is usually called the game’s design.
This glossary defines the common building blocks. It deliberately uses no real numbers, because the values attached to mechanics differ in every game and change as games are updated.
Core terms
Player action and input
An action is something you can do: move, aim, block, interact. An input is the button press or gesture that triggers it. Designers decide which actions exist and how hard or easy they feel to perform.
Rules and goals
Rules set what is allowed, and goals tell you what to aim for. A goal might be reaching an exit, surviving a wave or scoring more points than an opponent. Many games layer goals: a short-term one such as defeating an enemy, and a long-term one such as finishing a story.
Feedback
Feedback is how a game tells you the result of an action: a sound when you hit something, a number floating up, a flash of light. Good feedback helps players understand cause and effect. This overlaps with game interfaces and sound design.
Health and damage
Hit points
Hit points, often shortened to HP, measure how much damage a character or object can take before being defeated. Some games use a bar, others use a count of hearts or simply let a single hit end the attempt. Healing restores hit points.
Damage and armour
Damage reduces hit points. Armour or defence is a mechanic that lessens the damage received. Designers use these to make some opponents tougher than others without changing how the player attacks.
Cooldown
A cooldown is a waiting period before an ability can be used again. It controls how often powerful actions occur. A long cooldown makes each use a decision, while a short one lets players use abilities frequently.
Resources
Resource
A resource is something you collect and spend: money, ammunition, energy, wood, time. Resources create choices because you cannot have everything.
Source and sink
A source is where a resource enters the game, such as a reward from a quest. A sink is where it leaves, such as buying equipment or repairing items. If sources outpace sinks, a resource can lose its value, and balancing this is central to game economies.
Stamina and mana
Stamina limits physical actions like sprinting or dodging, and mana limits magical ones. Both recover over time or through items. They stop a player from using the best option constantly.
Growth and structure
Progression
Progression is how a player becomes more capable or moves through the game. It may come through levels, new gear, unlocked areas or learned skill. Different forms are compared in progression systems.
Skill tree
A skill tree is a diagram of abilities you can unlock, often with some depending on others. It lets players shape their character, which links to character builds.
Crafting
Crafting lets you combine collected items into new ones. A crafting loop describes the cycle that follows: gather materials, craft something better, use it to reach harder places, and gather more. Loops like this give a game a repeating rhythm.
Core loop
The core loop is the basic cycle of actions the player repeats, such as explore, fight, collect, upgrade. Designers often describe a game by its core loop because it shows what you will mostly be doing.
Challenge and chance
Difficulty
Difficulty is how demanding a game is. Designers adjust it through enemy toughness, timing windows, resource scarcity and more. The effect on enjoyment is discussed under game difficulty.
Randomness
Randomness introduces chance, for example in damage ranges or item rewards. Some players enjoy the surprise; others prefer predictable outcomes. Procedural generation is a related technique that creates levels or items from rules rather than hand design.
Checkpoints and saving
These let a player recover progress after failure. They are a mechanic, because they change how risky each attempt feels.
How mechanics fit together
Mechanics rarely work alone. Consider a simple action game. You fight enemies, which costs hit points and uses abilities limited by cooldowns. Winning gives experience and loot, which feed progression. Loot can be crafted into better equipment, letting you take on tougher enemies. That is one loop, assembled from several small mechanics.
Changing one part affects the others. If a designer lengthens a cooldown, fights take more careful timing. If healing items become scarce, hit points matter more. This is why updates to a game can change how it feels even when only one setting moves, and why how game systems fit together is a topic of its own.
Reading design language
When a developer says a mechanic is “tight” or “clunky”, they are usually describing responsiveness and feel rather than the rule itself. When players say a mechanic is “broken”, they often mean it is so strong that it undermines the rest of the design. These words are opinions, so look at what the mechanic does before accepting the label.