The foundational design discipline — the spine the rest of the pack cross-links to. Use when judging whether a mechanic is fun, auditing a system for balance, designing difficulty/flow, setting reward schedules, checking player motivation, or diagnosing "my choices don't matter" / "this is grindy" / "this difficulty spike feels cheap". Covers interesting decisions (Sid Meier), flow & difficulty curves, intrinsic/extrinsic motivation (Self-Determination Theory), feedback & agency, and choice architecture. Triggers on "is this fun", "interesting decision", "dominant strategy", "balance this", "difficulty curve", "flow", "reward schedule", "player motivation", "fake choice", "analysis paralysis", "one more turn".
インストール
Codex または Claude でインストール この Prompt をコピーして Codex、Claude、または他のアシスタントに貼り付けると、Skill ページを確認してインストールできます。
The foundational design discipline — the spine the rest of the pack cross-links to. Use when judging whether a mechanic is fun, auditing a system for balance, designing difficulty/flow, setting reward schedules, checking player motivation, or diagnosing "my choices don't matter" / "this is grindy" / "this difficulty spike feels cheap". Covers interesting decisions (Sid Meier), flow & difficulty curves, intrinsic/extrinsic motivation (Self-Determination Theory), feedback & agency, and choice architecture. Triggers on "is this fun", "interesting decision", "dominant strategy", "balance this", "difficulty curve", "flow", "reward schedule", "player motivation", "fake choice", "analysis paralysis", "one more turn".
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)
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.