Summary

An interaction loop is the repeatable cycle through which a player learns, tests, and refines a skill. Students usually meet this idea through questions like “how do players learn mechanics?”, “how do I teach without a tutorial pop-up?”, or “why does a mechanic stop engaging people?” The LDARF model (Learn → Decide → Action → Rules → Feedback) answers those questions by breaking every mechanic into a visible learning cycle, while skill chains show how simple loops connect into more advanced mastery. (course lecture series, see source-player-psychology-lectures)

For the broader theory behind why skill acquisition is pleasurable, see fun-as-learning.

Key ideas

The player model

The player is an entity driven — consciously or subconsciously — to learn new skills of high perceived value. They gain pleasure from successfully acquiring those skills. (see fun-as-learning, neurochemical-engagement)

This model has two critical components:

  • Driven to learn: Play is instinctual. In the absence of more pressing demands, people begin playing by default. Boredom and frustration are feedback mechanisms that prod players toward more stimulating challenges.
  • Perceived value: The perception of a skill’s value matters more than its objective value. Players will invest enormous effort into skills they believe will help them progress — and rapidly abandon skills that feel pointless.

The LDARF interaction loop

A game interaction loop describes the repetitive sequence through which a player learns and uses a specific skill. The five components:

StageDescription
LearnPlayer encounters something new — a mechanic, enemy, obstacle. They begin building a mental model.
DecidePlayer evaluates options: What can I do here? What’s the cost? What’s the benefit? What alternatives exist?
ActionPlayer executes an input — button press, movement, placement, spoken choice.
RulesThe game’s systems process the action. These rules are initially a black box — unknown to the player, but learnable through repetition.
FeedbackThe game responds. This response updates the player’s mental model and feeds back into the Learn stage.

The loop then repeats, each iteration refining the player’s understanding until mastery is achieved — what Koster calls grokking: understanding a causal link with certainty and being able to repeatedly cause the desired effect (see fun-as-learning).

Learning through cause and effect:

  • Association — “When I do something, something happens” (fuzzy)
  • Sampling — The more they practise, the more certain they become
  • Grokking — They understand the causal link with certainty and can exploit it reliably

Skill chains

Individual interaction loops are not isolated — they form a directed graph called a skill chain. Simpler skills must be mastered before higher-complexity skills become accessible. Mastery flows down the chain.

[Jump] → [Double Jump] → [Wall Jump] → [Air Dash]
                 ↓
          [Jump Attack] → [Aerial Combo]

Case study: Zelda: Breath of the Wild skill chain atoms:

  • Basic Movement: Walking → Running → Jumping
  • Exploration: Climbing → Swimming → Gliding
  • Puzzle Solving: Magnesis → Cryonis → Remote Bombs
  • Combat: Basic Attack → Advanced Attack → Dodge/Block
  • Crafting: Collecting Materials → Cooking → Making Potions

Feedback loops within the chain:

  • Positive: Successfully defeating enemies with advanced combat rewards better loot, incentivising further skill development
  • Negative: Failing a shrine puzzle resets it, encouraging the player to reconsider their approach

Skill status

Every skill atom in the chain has a status reflecting the player’s current relationship to it:

StatusDescription
UnexercisedThe player has not yet attempted this skill
ActiveThe player is practising — building mastery (can become a grind)
Partially MasteredThe player has some command but not fluency
MasteredThe player has achieved reliable, fluent use
Burned OutThe player mastered it but has lost interest in using it

Mastery must flow from foundational atoms. If a player is blocked early in the chain, they will never reach the further atoms — even if those atoms are well-designed.


Skill failure — diagnostic model

When players fail to learn a skill, the failure can be traced to a specific point in the LDARF loop:

Loop stageFailure modeCommon causes
LearnPlayer didn’t build the right mental modelIncomplete prerequisite skills; insufficient learning time; wrong schema
DecidePlayer chose not to engagePerceived cost too high; perceived benefit too low; better alternatives existed
ActionPlayer couldn’t executePhysical difficulty; controls unclear; required technique not yet taught
RulesCausal link wasn’t learnableRules too dynamic (no consistent pattern); too complex to convert to cause/effect
FeedbackPlayer didn’t receive or process feedbackNo feedback present; feedback ignored; multiple competing stimuli masked it
BurnoutPlayer mastered but disengagedSkill no longer provides novelty or perceived value

Critical insight: Learning failures are almost always design failures, not player failures. If the majority of players cannot learn a skill, the problem is in the architecture — the prerequisite chain, the feedback, or the perceived value — not in the players.


Skill trees

A skill tree is the UI manifestation of a skill chain — a graphical representation of the progression of skills, abilities, or upgrades that a player can unlock. It makes the otherwise implicit directed graph visible and navigable.

Functions:

  • Customisation — players choose paths aligned to their playstyle, making each run unique
  • Progression signal — unlocking nodes provides explicit acknowledgement of advancement
  • Strategic depth — choices about which path to pursue create meaningful decisions
  • Replayability — different build paths encourage multiple playthroughs

Player types and motivation

The course lecture series reference several player type taxonomies relevant to skill motivation:

  • Bartle’s Taxonomy (Achievers, Explorers, Socialisers, Killers)
  • Yee’s Gamer Motivation Model
  • Lazzaro’s Four Keys to Fun
  • Self-Determination Theory applied to gaming (see self-determination-theory)

Different player types will value different kinds of skill mastery — a competitive player prizes combat skill chains; an explorer prizes navigation and discovery chains.

Practice

Choose a game you know well and pick one mechanic it introduces part-way through (a new enemy, a grappling hook, a parry, a crafting station).

Part A: write the mechanic’s LDARF loop as a five-row table (Learn, Decide, Action, Rules, Feedback), describing what actually happens at each stage in this game. Underneath, note when you moved from association to sampling to grokking.

Part B: draw a skill chain of five to eight skill atoms that leads to one advanced skill, with arrows from each prerequisite to the skill that depends on it (as in the Jump → Double Jump example). Label each atom with its current skill status for you.

Success test:

  • all five LDARF stages contain concrete, game-specific detail
  • the Feedback row names a specific signal the game gives (a sound, an animation, a number, a state change)
  • the Rules row describes something you had to learn through repetition, not something the game told you
  • every arrow in the chain means “must be mastered before”
  • every atom carries one of the five statuses: Unexercised, Active, Partially Mastered, Mastered or Burned Out

Extension:

  • pick a skill where you or a friend got stuck, use the skill-failure diagnostic table to name the loop stage where the learning failed, and propose one design change aimed at that stage

Self-test

  1. What are the five stages of the LDARF loop?
  2. Why is the Rules stage described as a “black box” at first?
  3. What does Koster mean by grokking, and which two stages of cause-and-effect learning come before it?
  4. What is a skill chain, and why does a block early in the chain matter so much?
  5. A player has mastered a skill but no longer wants to use it. What is that skill’s status?
  6. If most players cannot learn a skill, where does this page say the problem usually lies?

Answers

  1. Learn, Decide, Action, Rules, Feedback.
  2. The game’s rules are initially unknown to the player; they become learnable only through repeated actions and the feedback those actions produce.
  3. Grokking is understanding a causal link with certainty and being able to cause the desired effect repeatedly; it follows association (fuzzy “I do something, something happens”) and sampling (growing certainty through practice).
  4. A skill chain is a directed graph in which simpler skills must be mastered before higher-complexity skills become accessible; if a player is blocked early, they never reach the later atoms, however well designed those are.
  5. Burned Out.
  6. In the design rather than the players: the prerequisite chain, the feedback, or the perceived value of the skill.

  • source-player-psychology-lectures

  • game-atoms — the atomic loop (Action → System Response → Feedback → Understanding → Next Action) is the same cycle described from the game’s side

  • fun-as-learning — Koster’s theory that fun is the process of learning patterns and grokking them

  • game-loops — the broader loop structure (core, inner, outer) that skill chains operate within

  • flow — the channel of balanced challenge and skill that skill chains help maintain

  • challenge-types — Adams’ taxonomy of challenge types; skill chains generate different challenge types

  • player-agency — agency requires skill — without learnable mechanics, meaningful choice collapses

  • self-determination-theory — SDT’s competence need explains why skill acquisition is intrinsically motivating

  • prototyping — prototyping core loops tests whether the skill chain is learnable before full development

  • source-game-design-lectures

  • source-theory-of-fun

  • breath-of-the-wild — Systemic design behind the BotW skill-chain case study