Summary
Games offer players challenges to overcome using available actions. Adams (Ch. 13) describes a set of broad categories of challenge (this page covers eleven, from physical coordination to creation and construction), each with subcategories and design guidance for adjusting difficulty. Understanding challenge types helps designers build varied, well-paced gameplay and avoid common errors. All challenges in a game nest into a hierarchy topped by the overall goal.
(Adams, Fundamentals of Game Design, see source-fundamentals-game-design)
Hierarchy of challenges
Challenges at every scale form a hierarchy:
Win the game
└── Complete Level 1
└── Sub-mission 1: Find item
└── Atomic: win fight
└── Atomic: solve puzzle
└── Atomic: find item ← player's current focus
- Atomic challenges: the indivisible, immediate challenges the player faces at any moment
- Sub-missions / missions: groups of atomic challenges organised toward intermediate goals
- Game goal: the topmost challenge; completing all missions wins the game
Players focus attention on atomic challenges but hold higher-level challenges in mind — creating anticipation. Designers should always tell players the overall goal and the atomic-level actions. Intermediate levels are typically left for the player to discover.
Simultaneous challenges: players may face multiple atomic challenges at once (vertically and horizontally in the hierarchy). More simultaneous challenges → more stress; more levels managed at once → more cognitive complexity.
Difficulty
Intrinsic skill required
The level of skill needed to surmount a challenge given unlimited time. Independent of any time pressure. Examples: the precision required to hit a target at range; the depth of a sudoku puzzle.
Stress
The difficulty added by time pressure. A challenge requiring little intrinsic skill can still be stressful if the player must complete it very quickly (e.g. Tetris). Stress raises heart rate and demands faster reactions.
Absolute difficulty
“The absolute difficulty of a challenge consists of a combination of the intrinsic skill required to meet the challenge without time pressure and the stress added by time pressure.” — Adams, Ch. 13
To adjust difficulty:
- More time pressure → more stress; less → less stress
- Raise intrinsic requirement (target smaller, puzzle deeper, more enemies) → harder
- Provide more time when raising intrinsic skill (inverse relationship preserves difficulty level)
Challenge categories
Physical coordination
Tests hand-eye coordination, motor skill, reaction speed, timing.
| Subcategory | Description | Examples |
|---|---|---|
| Speed and reaction time | Fast inputs, rapid responses | Tetris, shooters |
| Accuracy and precision | Steering, shooting, positioning | OutRun, Rainbow Six |
| Intuitive physics | Internalising game physics models | Angry Birds, vehicle sims |
| Timing and rhythm | Correct action at the correct moment | Dance Dance Revolution, Guitar Hero |
| Combination moves | Memorised sequences under time pressure | Street Fighter, fighting games |
To make easier: give more time; widen input tolerance; add aim assist. Most physical challenges scale directly with time pressure — remove the clock to reduce stress.
Logic and mathematics
Formal deductive reasoning or probabilistic calculation.
- Formal logic puzzles: closed systems solvable by reasoning alone (Rubik’s Cube, Minesweeper, Professor Layton). Must always have a discernible solution state — puzzles solvable only by trial and error are bad design.
- Mathematical challenges: probability reasoning (poker, craps), implicit numeric relationships (damage formulas, economic ratios).
“Design Rule: Avoid trial-and-error solutions. Solving most logic puzzles requires experimentation, but the player must be able to make deductions from her experiments.” — Adams, Ch. 13
Races and time pressure
Accomplishing something before an opponent or deadline. Time pressure discourages careful strategic thought and encourages direct, brute-force solutions. Use judiciously — adding time pressure to challenges that don’t inherently need it makes them harder without making them more interesting.
Factual knowledge
Tests knowledge the player brings from outside the game world. Generally confined to trivia/quiz games. If factual knowledge from the real world is required in any other game, this must be stated clearly in advance — it breaks immersion and punishes players for lacking arbitrary external knowledge.
Memory
Recalling objects, sequences, or patterns observed earlier in the game. Players can defeat memory challenges by taking notes, so add time limits if recall is central. Often combined with exploration challenges.
Pattern recognition
Identifying visible or behavioural patterns.
- Static patterns: match-3 grids (Bejeweled, Candy Crush)
- Behavioural patterns: enemy attack sequences, boss patterns, movement cycles
To make easier: shorter, simpler, more obvious patterns; hints after a short delay. To make harder: longer, more intricate, more subtle patterns.
Exploration
Moving into and mapping unfamiliar space.
| Subcategory | Description | Design notes |
|---|---|---|
| Spatial awareness | Learning one’s way around a complex 3D space | Maps (with or without player location) help |
| Locked doors | Any barrier requiring the player to unlock or overcome | Avoid unmarked switches far from the door |
| Traps | Hazards that harm the player when triggered | Fun comes from outwitting traps, not falling in them |
| Hidden regions | Areas requiring extra effort or observation to find |
Conflict
Player versus other agents (human or AI).
| Subcategory | Examples |
|---|---|
| Strategy, tactics, logistics | Warcraft, commanding armies |
| Survival | Pac-Man, avoiding being caught |
| Reduction of enemy forces | Space Invaders |
| Defending vulnerable items | Ico, tower defence |
| Stealth | Assassin’s Creed |
Economic challenges
Managing resources, production, and exchange.
| Subcategory | Examples |
|---|---|
| Accumulating resources/growth | Civilization |
| Establishing efficient production | The Settlers |
| Achieving balance/stability | SimEarth |
| Caring for living things | The Sims |
See internal-economy for the design model underlying economic challenges.
Conceptual reasoning and lateral thinking
Piecing together non-obvious solutions from incomplete information.
- Sifting clues from red herrings
- Understanding social relationships (Façade)
- Detecting hidden meanings (Planescape: Torment)
- Lateral thinking (The Incredible Machine)
Creation/construction
Aesthetic success or functional construction.
- Aesthetic: assembling something beautiful (The Sims photo album)
- Functional: building with a goal (Minecraft)
In practice
Designing challenge variety: Use multiple categories within a game to avoid monotony. Even a pure action game can include exploration, pattern recognition, and memory challenges.
Designing challenge hierarchy: Sketch the hierarchy before detailing atomic challenges. Ensure the hierarchy reads coherently — each atomic challenge should contribute to a sub-mission, each sub-mission to a mission.
Balancing intrinsic skill and stress: When raising difficulty, choose whether to increase skill requirement, time pressure, or both. Preserve an inverse relationship when possible: more skill required → more time allowed; more time pressure → less intrinsic skill required.
Avoiding common errors:
- Never require trial-and-error for logic puzzles — always provide deductive clues
- Never require outside factual knowledge without declaring it in advance
- Avoid unmarked switches or traps discoverable only by failure
- Inform players of their short-term goals at all times
Open questions
- Adams’ taxonomy is based on practical observation rather than empirical research. Are there challenge types missing from his list? (Relational/social challenges, for instance, are not explicitly categorised.)
- How do challenge types map to MDA aesthetics? Physical coordination maps naturally to Sensation/Challenge; exploration maps to Discovery; creation maps to Expression.
Practice
Map the challenges in one level of a game you know well, such as a world in Super Mario Bros., a Portal test chamber or a single area of a Metroidvania. Choose a section that takes 10 to 15 minutes to play, then play it or watch a recording and:
- list every atomic challenge in the order you meet it
- tag each one with a category from this page (physical coordination, logic, exploration, conflict and so on) and a subcategory where one fits
- note whether each challenge’s difficulty comes mainly from intrinsic skill, from stress (time pressure) or from both
- draw the hierarchy: game goal, then the level, then its sub-missions, then the atomic challenges
Success test:
- every atomic challenge has one primary category, with a second only where two genuinely overlap
- at least three different categories appear, or you can explain why the level relies on only one or two
- every atomic challenge connects to a sub-mission in your hierarchy diagram
- you can point to one moment where challenges are simultaneous and say whether it adds stress, cognitive complexity or both
Extension:
- make one challenge easier without removing it, using this page’s advice (more time, wider input tolerance, a simpler pattern, a hint after a short delay), and say which part of absolute difficulty you changed
Self-test
- What is the difference between the intrinsic skill a challenge requires and the stress it adds?
- You make a puzzle deeper. What does the page suggest you change at the same time if you want the overall difficulty to stay the same?
- Why does Adams treat logic puzzles that can only be solved by trial and error as bad design?
- Name the levels of the hierarchy of challenges, from the bottom to the top.
- According to the page, what should a designer always tell the player, and what is usually left for the player to discover?
- When is a factual knowledge challenge acceptable in a game that is not a quiz game?
Answers
- Intrinsic skill is the skill needed to overcome the challenge given unlimited time. Stress is the extra difficulty added by time pressure.
- Give the player more time. Keeping skill and time pressure in an inverse relationship preserves the difficulty level.
- The player must be able to make deductions from their experiments, and the puzzle must have a discernible solution state. Guessing alone is not reasoning.
- Atomic challenges, then sub-missions and missions, then the game goal.
- Always tell the player the overall goal and the atomic-level actions. The intermediate levels are typically left for the player to discover.
- Only when the need for that real-world knowledge is stated clearly in advance.
Related
- game-balance — Difficulty calibration; perceived difficulty formula
- flow — Challenge types must be matched to player skill level to maintain flow
- mda-framework — Challenge types correspond to different aesthetic goals
- internal-economy — Economic challenge design
- level-design — Level designers select and sequence challenge types
- player-centric-design — Challenge design must match representative player capability
- source-fundamentals-game-design