rbergman/progression-systems

Progression Systems

Purpose: Tools for designing how players grow in power, skill, and access over time. Good progression makes every session feel rewarding. Bad progression creates grind, frustration, or trivialized content.

Influences: Frameworks here draw on systematic balance methodology (power curves, pacing math), experience engineering theory (accessibility/depth model), cognitive UX research (flow channel, cognitive pacing), and flow theory from positive psychology.

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When to Activate

Use this skill when:

• Designing XP curves, level-up formulas, or unlock schedules
• Tuning difficulty ramps for a campaign or level sequence
• Players report the game is "too easy," "too hard," or "grindy"
• Implementing adaptive difficulty or dynamic scaling
• Planning content pacing for a long-form game
• Deciding what to gate behind progression vs. make available from the start

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Core Model: Accessibility and Depth

Two independent axes that progression systems must serve:

Depth (high ceiling)
    |
    |   +-----------+
    |   | The Goal  |   ← Easy to start, deep to master
    |   +-----------+
    |
    +-------------------→ Accessibility (low floor)

• Accessibility (low floor) — Can a novice play and have a good time?
• Depth (high ceiling) — Is there room for an expert to keep improving?

These are NOT opposites. The best systems score high on both. Techniques:

| Technique | How It Works | Example | |-----------|-------------|---------| | Layered complexity | Simple surface, deep internals | Chess: easy rules, infinite strategy | | Optional complexity | Advanced systems exist but aren't required | Type matchups you can ignore if you over-level | | Skill-based progression | The player improves, not just the character | Combo execution, map knowledge, timing |

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Power Curves

How player power grows over time. The curve shape determines how the game feels.

Curve Types

Power
  |          Exponential        S-Curve (often ideal)
  |         /                  _____
  |        /                  /
  |       /                  /
  |      /                  /
  |     /                  /
  |    /              ____/
  |   /              /
  |  /              /
  | /           ___/
  |/___________/
  +----------------------------------→ Time

  Linear                    Logarithmic
  /                         ___________
  /                        /
  /                       /
  /                      /
  /                     /
  +-------------------→  +-------------------→

| Curve | Feel | When to Use | Risk | |-------|------|-------------|------| | Linear | Consistent, predictable | Tutorial sections, first hour | Boring over long spans | | Exponential | Dramatic, accelerating | Short games, power fantasies | Unmanageable late game | | Logarithmic | Diminishing returns | Realistic simulations | Feels unrewarding as ceiling approaches | | S-Curve | Slow start → rapid middle → plateau | Most progression systems | Requires careful inflection point placement |

Felt vs. Actual Power

Players need to feel stronger even when mathematical power growth slows.

Techniques for maintaining felt power at diminishing actual power:

• New abilities that look dramatic even if numerically modest
• Visual upgrades (armor appearance, particle effects, screen presence)
• New types of interaction rather than bigger numbers
• Areas of the world that were previously inaccessible
• AI enemies that react more dramatically to the player's attacks

Template: Power Curve Spreadsheet

| Level | XP Required | Cumulative XP | Power Rating | Felt Power | New Content |
|-------|-------------|---------------|--------------|------------|-------------|
| 1     | 0           | 0             | 10           | Low        | Tutorial    |
| 2     | 100         | 100           | 15           | Growing    | Ability A   |
| 3     | 150         | 250           | 19           | Growing    |             |
| 4     | 225         | 475           | 22           | Moderate   | Area B      |
| 5     | 340         | 815           | 25           | Moderate   | Ability B   |

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XP and Level Math

Common XP Formulas

Linear scaling: xp_for_level(n) = base * n

• Simple, predictable, gets grindy fast

Polynomial: xp_for_level(n) = base * n^exponent

• Exponent 1.5-2.0 is common
• Gradually increasing time between levels

Exponential: xp_for_level(n) = base * growth_rate^n

• Dramatic acceleration, use sparingly
• Works when matched with exponential reward scaling

Practical approach:

1. Decide how long each level should feel in play time
2. Estimate XP gain per minute of intended play
3. Back-calculate the required XP per level
4. Plot and smooth the curve
5. Playtest and adjust — the math is a starting point, not the answer

Level Count Rule of Thumb

Target a level-up every 10-30 minutes of play in the early game, stretching to 30-60 minutes in mid/late game. Work backward from intended game length to determine level count. Short games (2-5 hours) need fewer levels (10-15); long games (50+ hours) need more (50-100) but risk grind at scale.

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The Flow Channel

Challenge should approximate skill level — the "flow channel" from psychology:

Challenge
    |     Anxiety
    |    /
    |   /  FLOW CHANNEL
    |  /  /
    | /  /
    |/  /
    | /  Boredom
    |/
    +------------------→ Skill

• Above the channel → anxiety, frustration, quitting
• Below the channel → boredom, disengagement
• In the channel → engagement, "just one more try"

Targeting the Channel

• [ ] Does difficulty scale with demonstrated player skill (not just time played)?
• [ ] Are there multiple difficulty signals? (Speed, accuracy, strategy quality, not just "did they die?")
• [ ] Does the channel widen as skill increases? (Experts tolerate more variance)
• [ ] Can players self-select difficulty? (Options, optional challenges, difficulty modes)

Adaptive Difficulty

If implementing dynamic difficulty adjustment (DDA):

Do:

• Adjust invisibly (enemy spawn rate, AI aggression, resource availability)
• Base adjustments on multiple signals (death rate + time-to-complete + resource usage)
• Apply gradually — sudden shifts feel unfair

Don't:

• Make it visible — players who notice rubber-banding feel cheated
• Adjust core challenge identity (if the game is about precision, don't make hitboxes bigger)
• Scale only HP/damage (lazy, breaks balance, doesn't change the experience)

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The Difficulty Sandwich

Good progression peels three layers of challenge:

Layer 1 (bottom):  Mechanical skill     (can I physically do this?)
Layer 2 (middle):  Cognitive challenge   (do I understand what to do?)
Layer 3 (top):     Strategic depth       (can I optimize my approach?)

Progression phases:

• Early game: Layer 1 only — learn controls, build muscle memory
• Mid game: Layer 1 + 2 — learn systems, understand interactions
• Late game: All three — master strategy, optimize builds, find efficiencies

Anti-pattern: Introducing Layer 3 challenges before Layer 1 is comfortable. Don't ask for strategic thinking while the player is still fumbling with controls.

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Content Pacing

New content (mechanics, enemies, zones, abilities) should arrive at inflection points on the power curve.

Rules of thumb:

• Introduce new content when the player has just mastered the previous content
• Each new element should change how the player plays, not just what they fight
• Space unlocks so there's always something recent to explore and something to anticipate
• The longest stretch without new content should be shorter than the player's patience — and that's shorter than you think

Unlock Pacing Checklist

• [ ] Is there a meaningful unlock or new mechanic every 15-30 minutes? (Adjustable per genre)
• [ ] Do unlocks change player behavior? (New ability that opens new tactics > +5% damage)
• [ ] Is there always a visible "next milestone" to work toward?
• [ ] Does the pacing slow down as the player's investment deepens? (Acceptable late-game)
• [ ] Are early unlocks front-loaded to hook new players?

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Common Pitfalls

• Flat difficulty that doesn't respond to player growth (level 50 feels like level 5)
• Rubber-banding that's visible and feels unfair ("the game cheated")
• Difficulty modes as HP/damage scaling (lazy, breaks balance, doesn't change experience)
• Punishing experimentation in the learning phase (deaths should teach, not just frustrate)
• Power creep in sequential content releases (each new thing must be "better" to sell)
• Grind without purpose — repetition is acceptable when each cycle teaches something; it's toxic when it's just time-gating

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Cross-References

• motivation-design — The psychology behind progression. This skill covers the math; motivation-design covers why players respond to progression and when extrinsic rewards help vs. hurt
• economy-design — Progression economy: XP as currency, level-gated purchases, power-to-earning feedback loops
• systems-design — How progression interacts with other systems; progression is typically the most critical system for retention
• game-balance — Power curves must align with cost curves; balance changes affect progression feel
• experience-design — Pacing and engagement loops at the macro level
• encounter-design — Difficulty through encounter design rather than stat scaling
• player-ux — Onboarding is the first phase of the progression curve; cognitive load constrains pacing
• game-feel — Felt power is heavily influenced by feedback quality
• playtest-design — Testing whether difficulty is in the flow channel for your target audience