Progression systems are everywhere in games.
Leveling up. Unlocking content. Improving stats. Scaling difficulty.
But most players don’t think in terms of curves or formulas.
They feel something else:
- momentum
- fairness
- excitement
- frustration
Behind all of that is a simple idea:
Progression is the relationship between effort and reward over time.
And that relationship is defined by curves.
Progression Is Not Just Growth — It’s a Tradeoff
At its core, progression is not about “getting stronger.”
It’s about trading one resource for another:
- time - XP
- effort - skill
- currency - power
- attention - progress
This is why progression is tightly connected to economy design.
Every system answers the same question:
How much should a player give to get something in return?
The Hidden Layer: Relationships Between Numbers
Numbers in games don’t exist in isolation.
A sword that deals 250 damage is meaningless unless:
- enemies have 25,000 HP
- or 200 HP
- or your previous weapon did 50
As noted in game economy theory, numbers only make sense in relation to other numbers .
This is where curves come in.
A curve is simply:
How one resource changes as another increases.
The Core Curve Types (and When They Break)
Identity (1:1)
The simplest possible relationship.
- 1 point → 1 stat
- 1 resource → 1 outcome
Useful for clarity, but often too flat to drive interesting decisions.
Linear (y = mx)
Predictable scaling.
- +10 power → +100 cost
- steady, consistent growth
Good for:
- readability
- balance stability
Bad for:
- excitement
- long-term engagement
Exponential (y = a^x)
The most seductive — and dangerous — curve.
- slow start
- rapid escalation
- extreme late-game values
Used for:
- early progression acceleration
- creating long-term goals
The Problem
Exponential curves break at scale.
They:
- create grind walls
- inflate numbers beyond meaning
- force designers to intervene
That’s why most systems:
- cap them
- flatten them
- or transition into custom curves later
Triangular (Controlled Growth)
A middle ground between linear and exponential.
They:
- increase steadily
- avoid runaway scaling
- feel “natural” to players
This is why they appear often in:
- board games
- progression systems
- resource costs
Custom-Crafted Curves (The Real World)
In practice, most systems are hand-tuned.
Designers:
- break patterns intentionally
- introduce irregularities
- adjust for perception, not math
Because perfectly smooth curves often feel… wrong.
Why Smooth Systems Feel Bad
A perfectly balanced system can still feel terrible.
Why?
Because players don’t experience math.
They experience contrast.
That’s why designers add:
spikes → sudden power, breakthroughs
valleys → weakness, tension
These create:
- memorable moments
- emotional pacing
- perceived progression
Without them, systems feel flat and forgettable.
Shared Resources: Where Systems Collide
The real complexity appears when systems share resources.
Example:
gold used for:
- upgrades
- crafting
- progression
Now every decision becomes a tradeoff.
This is where:
- strategy emerges
- friction appears
- balance becomes fragile
The Real Challenge: Multi-Player-State Design
Live games introduce a deeper problem.
You’re not designing one progression system.
You’re designing for multiple players at once:
- new players → need fast onboarding
- mid-game players → need structure
- long-term players → need stability
These goals conflict.
A change that helps onboarding can:
- inflate the economy
- devalue progression
- break long-term balance
This is why many systems feel like compromises.
Hybrid Systems: Predictable + Random
Modern games often combine:
steady progression → structure, fairness
random rewards → excitement, unpredictability
This hybrid approach:
- maintains engagement
- controls pacing
- hides system complexity
But it also introduces risk:
- perceived unfairness
- loss of player trust
Progression and Monetization
In free-to-play systems, curves are not just design tools.
They are business tools.
Designers may:
- slow progression at key points
- introduce friction strategically
- create resource scarcity
Sometimes even:
- obscure real-world value through multiple currencies
The goal is not just balance.
It’s retention and conversion.
Sidequest: Analyzing a Real Game
Take any game with levels.
- Plot:
- X-axis - Level
- Y-axis - XP required
- Observe:
- Does it start exponential?
- Does it flatten later?
- Are there spikes or irregularities?
In most cases, you’ll find:
- early game - fast progression
- mid game - structured growth
- late game - controlled slowdown
Because pure curves rarely survive real players.
The Real Insight
Progression is not a math problem.
It’s a perception problem.
Players don’t ask:
- “Is this curve correct?”
They ask:
- “Does this feel fair?”
- “Does this feel rewarding?”
- “Does this respect my time?”
Final Thought
If your progression system feels wrong, the issue is rarely:
“the numbers are off”
It’s usually:
“the relationship between effort and reward feels broken”
Fix the relationship - not just the numbers.
Further Exploration
[https://itembase.dev/blog-curves.html]After reading this blog, I realized that progression systems are not just about numbers or formulas.
Good progression is not mathematically correct, it feels correct to the player.
How do you approach progression systems in your projects?
Do you design the curve first, or the player experience?