Summary
An interest curve is a graph of player/audience interest (y-axis) over time (x-axis) for an entertainment experience. The concept comes from Jesse Schell’s The Art of Game Design, where it is introduced as one of his earliest and most practically useful design tools.
The core insight: it is not only what happens in a game or show that determines its quality, but when it happens and in what order. The same content arranged poorly will underperform relative to the same content arranged well.
(Schell, The Art of Game Design, see source-art-of-game-design)
Key ideas
Anatomy of a good interest curve:
- (A) Initial interest — The guest arrives with some baseline expectation. Too much hype can inflate this and make the actual experience disappointing.
- (B) The hook — An early spike of interest that grabs attention and promises what is to come. In a videogame, often an opening cinematic or immediate action. Critical: a poor hook risks losing the audience before the experience unfolds.
- (C–F) Build with peaks and valleys — Interest generally rises, with temporary high points and brief dips for relief and anticipation. Constant high-intensity leads to exhaustion; constant low leads to boredom. The valleys are part of the structure.
- (G) Climax — The peak of the experience. The highest point of interest and engagement.
- (H) Resolution — Interest settles. Ideally, the audience leaves with more interest than they arrived with — “leave them wanting more.”
Signs of a bad interest curve:
- No hook — interest drops immediately
- Flat middle — no escalation, no variation
- Declining end — the best content comes too early
- Dropping below the interest threshold — the point where the player quits
In practice
Plot an interest curve before you build, and again after playtesting.
Before building: Sketch the intended curve for your level, session, or full game. Identify where the hook, peaks, valleys, and climax should fall. Check that no section is too long at a low interest level.
After playtesting: Observe where players disengage, get frustrated, or stop playing. Map this onto your intended curve to find divergences.
In Unity level design: Apply the interest curve to:
- Individual encounters within a level (enemy placement, pacing of obstacles)
- The level as a whole (introduction of mechanics, difficulty ramp, boss)
- The full game (tutorial arc, mid-game challenge, final act)
The pattern is fractal — it appears at every scale. A single level has an interest curve; so does each room within that level; so does each encounter within each room.
Example restructuring (from Schell): Schell and a fellow juggler initially ordered their routines from easiest to hardest, ending on their most technically impressive trick. After feedback, they reversed the emotional impact by reordering routines so interest built toward the finale — despite no content changing, audience response doubled.
Evidence
“The quality of an entertainment experience can be measured by the extent to which its unfolding sequence of events is able to hold a guest’s interest.” (Schell, The Art of Game Design, see source-art-of-game-design)
Schell identifies the same interest curve structure in: Hollywood three-act films, popular song structure (intro/verse/chorus/bridge/finish), Aristotle’s complication-and-denouement, the “rule of three” in comedy, rollercoaster track layouts, and individual levels in videogames.
Implications
- Pacing is design. The arrangement of moments matters as much as the moments themselves.
- Start strong. A weak opening is hard to recover from. The hook must come quickly.
- Plan your valleys. Downtime after a peak isn’t failure — it’s necessary. Players need breathing room before the next escalation.
- Know your climax. If you don’t know where the climax is, neither will your player.
Open questions
- How does the interest curve interact with player agency? In non-linear games, the “curve” is probabilistic — how do designers shape it without direct control?
- Does the optimal curve shape differ by genre? (e.g., horror games vs. puzzle games vs. action games)
Related
- design-lenses — Lens #61: The Lens of the Interest Curve; Lens #62: Inherent Interest
- flow — The related concept of moment-to-moment engagement balance
- game-feel — The micro-level of interest: responsiveness and juice
- level-design — Interest curves applied to spatial design
- playtesting — How to measure and observe actual interest curves
- source-art-of-game-design