game-design-fundamentals

game-design-fundamentals is a skill for Claude Code from rondorkerin/gamestack. It costs 156 tokens per session (634 once invoked), scanned A, original, MIT.

A foundation for making video-game mechanics, choices, difficulty, rewards, and progression enjoyable and meaningful.

In plain words
What is it for?
Use it to judge mechanics, balance systems, plan rewards and progression, shape difficulty and flow, and investigate player motivation.
Why use it?
It helps explain problems such as dominant strategies, difficulty spikes, grind, weak player choices, and confusing challenge.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the gamestack plugin — 26 skills shipped together

Good fit Use it to judge mechanics, balance systems, plan rewards and progression, shape difficulty and flow, and investigate player motivation.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/rondorkerin/gamestack/game-design-fundamentals
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add rondorkerin/gamestack --skill game-design-fundamentals
Clone the repo
git clone --depth 1 https://github.com/rondorkerin/gamestack

Made for: Claude Code.

Or install gamestack, the plugin that ships this one along with the rest of its 26 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for game-design-fundamentals

README.md
[![agentmods](https://agentmods.dev/badge/skills/rondorkerin/gamestack/game-design-fundamentals/github.svg)](https://agentmods.dev/skills/rondorkerin/gamestack/game-design-fundamentals)
Your own site
<a href="https://agentmods.dev/skills/rondorkerin/gamestack/game-design-fundamentals"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/game-design-fundamentals/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for game-design-fundamentals

Your own site · 80×15
<a href="https://agentmods.dev/skills/rondorkerin/gamestack/game-design-fundamentals"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/game-design-fundamentals.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 156 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 634 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00156 $0.00634
Opus 5 $0.00078 $0.00317
Sonnet 5 $0.00031 $0.00127
Haiku 4.5 $0.00016 $0.00063

Measured 12d ago against content hash d53f3ffd7762, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

game-design-fundamentals scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/gamestack/skills/game-design-fundamentals/SKILL.md · 38 lines

How it starts

The opening of the file, as written. The whole thing — 38 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Game-Design Fundamentals

The bedrock principles every other skill in the pack assumes. If a design decision feels wrong and you're not sure why, the answer is usually here.

When to use this

  • Deciding whether a mechanic, system, or choice is actually fun (not just functional)
  • Balancing — hunting dominant strategies, no-brainer options, difficulty spikes
  • Designing difficulty/flow, reward schedules, or progression
  • Diagnosing player complaints: "my choices don't matter", "it's grindy", "that death was cheap", "I'm overwhelmed"

Scope

This is the spine. Sibling skills specialize it and link back here:

  • Spatial reward cadence & exploration pull → open-world-design
  • Perceptual uniqueness / the oatmeal problem → procedural-generation, procgen-review
  • Telegraphing & fair lethality → combat-design, permadeath-and-lethality
  • Loot dominance & economy balance → rpg-systems
  • Real vs. fake branching → narrative-and-quest-design

How the pieces fit

  • GUIDE.md — the cited why: interesting decisions, flow & difficulty, motivation (SDT), feedback & agency, choice architecture. Each principle carries exemplars, sources, the named failure mode, and the procedural/headless implication.
  • CHECKLIST.md — Do/Don't + machine-checkable Test-for criteria, grouped by topic. These are written to be enforced as automated invariants in a generation loop, not just read.

The one idea to anchor on

A game is a series of interesting decisions (Sid Meier). A decision is interesting only when it has believed, persistent consequences, is made with enough information, carries a real trade-off, and has no dominant option. The single highest-leverage audit you can run: scan every system for a strictly-best strategy and delete it.

Why this matters doubly for a generator: a human team has a "this feels off" reflex that catches a broken economy or a cheap death late. An autonomous agent has none. So treat each principle here as an enforced automated invariant, not advice.

Read the full file on GitHub · 38 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 38 lines · 156 tokens per session scan A d53f3ffd7762

Subscribe to this mod's changes

game-design-fundamentals is a skill published in the GitHub repository rondorkerin/gamestack (28 stars, last pushed 2mo ago), licensed MIT. It adds 156 tokens to every session and 634 once invoked, about $0.0008 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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