Balancing Game Features

tim-cain game-design system-design balancing rpg combat-math

Abstract

Problem: How do you balance new weapons, spells, and abilities as they're added to an RPG, ensuring nothing is overpowered while keeping the player entertained?

Approach: Tim Cain describes his self-taught "stick a pin in it" method — an iterative process of fixing one variable at a time, deriving others from it, and revising when something doesn't work.

Findings: By pinning values sequentially (hit points → damage mitigation → damage output → creature HP), you build interlocking spreadsheets that let you evaluate any new feature against established baselines. The key metric is damage per second (DPS), which normalizes constant, spiky, and charge-up damage into comparable terms.

Key insight: Balance is achieved not by solving everything simultaneously, but by fixing one variable, deriving the rest, and unpinning only one thing at a time when adjustments are needed.

The "Stick a Pin in It" Method

Tim Cain was never formally taught how to balance game features. No class, no book, no conversation with another designer — he developed his approach through experience. He compares it to proof by contradiction in mathematics: you make an assumption, derive consequences, and if something comes out wrong, you go back and change the assumption.

The method is simple in principle:

  • Pick one thing and fix it ("pin it")
  • Derive other values based on that pinned value
  • Pin those too once you're happy with them
  • Expand outward to the next circle of related values
  • If something breaks, go back and unpin one thing, adjust, and recalculate

The critical rule: never pull out too many pins at once, or "everything just kind of falls apart."

Worked Example: Balancing an RPG

Tim walks through a concrete example of balancing a role-playing game, starting with a level 1 player.

Pin 1: Player Hit Points

Decide how many hit points the player starts with and how many they gain per level. Account for the full picture — items that grant temporary HP, perks that permanently change HP gain, attributes that modify the base. Establish a range (e.g., start at 50 HP, gain 5–20 per level depending on build). Write it all down in a spreadsheet.

Pin 2: Damage Mitigation

Determine how the player reduces incoming damage. This includes:

  • Armor — which may use Damage Resistance (DR, a percentage reduction), Damage Threshold (DT, a minimum damage requirement), or both
  • Skills like Block and Dodge — probabilistic avoidance that can be treated as effective DR (e.g., a 50% dodge chance ≈ 50% DR on average)
  • Healing — potions, spells, skills that restore HP mid-combat
  • Perks and other modifiers

Pin 3: Damage Output

Establish damage output for both players and creatures by level. This naturally produces ranges because weapons have damage ranges and hit chances introduce variance. Tim emphasizes calculating damage per second (DPS) as the universal metric, which lets you compare:

  • Constant damage — e.g., melee in The Outer Worlds (no to-hit roll, predictable output per round)
  • Spiky damage — miss, miss, then a big hit; or a mage's slow-casting powerful spell
  • Charge-up abilities — attacks that require buildup before unleashing (another form of spiky)

Pin 4: Creature Hit Points

Now that you know player damage output, decide creature HP based on how many combat rounds you want a fight to last. Pin that.

Step Back and Evaluate

With all four pins in place, you now have charts showing:

  • Player and creature HP by level
  • Damage mitigation per level
  • Damage output per level (for both sides)

Look at the emergent properties: How many rounds does a typical combat last? Do the numbers feel right? Does damage reduction feel meaningful (going from 100 to 99 damage taken is not impressive)? How does combat length change as you level up?

If something doesn't look right, unpin one thing, adjust, and recalculate.

Adding New Features

When introducing a new weapon, spell, or ability, the framework makes evaluation straightforward:

  • When does it enter the game? What player level do you expect?
  • How much damage should it do? You already have baseline DPS charts by level
  • How does it compare to existing weapons and abilities at that level?

Complexities to Account For

Tim acknowledges several factors that add depth to the calculations:

  • Damage types — normal, fire, acid, crushing, impaling, cutting — each may be mitigated differently
  • Multiple attacks per round — creatures or players may get several hits
  • Summoning — enemies that spawn reinforcements mid-combat multiply effective damage output
  • Difficulty scaling — if you want the game to feel harder at higher levels, reduce how many rounds creatures take to kill the player; most games accidentally get easier because spiky/charge abilities are harder to account for and players end up with more burst damage than expected

On the Craft

Tim notes this work involves "a lot of math" and recommends spreadsheets as essential tools. He emphasizes that the order of pinning doesn't matter — you could start with damage output and derive HP from it. What matters is the discipline of fixing variables one at a time and building outward.

He's never been taught this method, never discussed it with other designers, and has never seen a class or book that covers it. "Welcome to game design," he says.

Source: Balancing Game Features — Tim Cain's YouTube channel