Numerical Item Design

tim-cain game-design item-design systems balancing rpg

Abstract

Problem: How should designers approach item design in games — through numerical stat bonuses or unique non-numerical effects — and what are the tradeoffs of each?

Approach: Tim Cain breaks item design into two philosophies: numerical (stat-based bonuses) and non-numerical (unique gameplay-altering effects), analyzing the pros and cons of each from designer, programmer, and artist perspectives.

Findings: Numerical items are easy to design, code, and extend but struggle with excitement and artist workload at small incremental differences. Non-numerical items are aspirational and inspire creative builds but are harder to design, balance, compare, extend, and code.

Key insight: Neither approach is universally better — most games benefit from both, and player preference varies not just between people but between builds within the same game.

1. Context and Scope

Tim Cain responds to a community question about how items are designed in games, contrasting the "5% more fire damage" approach (Diablo-style) with the "weapon type affects your play style" approach (Monster Hunter-style). Before diving into numerical vs. non-numerical, he outlines prerequisites that must be settled first.

2. Prerequisites for Item Design

Before designing any items, designers must consider:

  • Setting — Fantasy vs. sci-fi determines item vocabulary (orbs vs. batteries, potions vs. drugs, scrolls vs. data chips)
  • Mechanics — Class-based vs. skill-based systems dictate what bonuses items should provide
  • Combat model — Turn-based items might grant earlier initiative or extra action points; real-time items might increase attack speed

3. Universal Item Design Principles

Regardless of philosophy, all items should be:

  • Aspirational — Players should want the better version, both in stats and visual appearance
  • Comprehensive — Enough items must exist to cover all viable player builds, class/race/skill combinations
  • Extensible — There should be an obvious upgrade path (a better version of each item)
  • Comparable — Players should be able to evaluate which item is better for their build, even if the choice isn't always clear-cut

4. Numerical Item Design

Numerical items primarily adjust game parameters: hit bonuses, critical hit chance, damage amounts (direct or DoT), attribute bonuses, or secondary stats like carry weight.

4.1. Pros

  • Easy to design — Parameters already exist in your rule system; items simply adjust them
  • Easy to code — Programmers collect parameter bonuses from equipped items and apply them in calculations. Values can be exposed to designers for tuning without code changes
  • Easy to extend and compare — A +20 damage sword is obviously better than a +10 damage sword, making progression clear and aspirational

4.2. Cons

  • Hard to make exciting — A 0.5% damage bonus or going from 50 to 51 damage doesn't generate much enthusiasm. Tim references EverQuest where +1 armor on a 1000-point scale felt meaningless
  • Artist nightmare — When the difference between two items is +10 vs. +11 stealth, artists must create hundreds of visually distinct assets for marginal stat differences. The better item should look better, but the differences are so small it becomes an impossible task at scale
  • Cross-category comparison difficulty — Comparing a pure damage weapon to one with a stealth bonus requires considering build, playstyle, and frequency of use — not a trivial decision despite both being "numerical"

5. Non-Numerical Item Design

Non-numerical items change how the player acts rather than making them incrementally better at what they already do. Examples: silent boots, a cloak that slows enemy detection, a shrink ray, paralysis effects, fear effects.

5.1. Pros

  • More aspirational and exciting — Polymorphing enemies into cats, chain explosions, knockbacks — these effects spark player imagination and inspire creative builds
  • Better for artists — Unique effects give artists something meaningful to design around, both for the item's appearance and its visual effects

5.2. Cons

  • Hard to compare — Is stunning better than knockback? It depends entirely on playstyle and context. Comparing two non-numerical items, or a numerical vs. non-numerical item, has no clean answer
  • Harder to design and balance — Requires creative ideation beyond parameter tweaking. Balance questions get complex: if polymorph turns someone into a fish, they just die — how do you balance that?
  • Extensibility problems — If an item causes explosions and the upgrade causes chain explosions, what's the next upgrade? The progression path isn't obvious
  • Much harder to code — Every non-numerical effect needs special code, tying into status effect systems, art systems, and animation systems. Tim notes that every science weapon in The Outer Worlds required its own special code, leading to more bugs, more debugging, and more testing

6. The Bottom Line

There is no universally correct approach. Some players prefer numerical items, some prefer non-numerical, and some switch preferences depending on their current character build. Tim advocates understanding both philosophies and their tradeoffs rather than picking one dogmatically.

Source: Tim Cain — "Numerical Item Design"

7. References