add-static-ability

A development guide for adding game rules that continuously change objects, such as their type, colour, strength, toughness, or keywords.

In plain words
What is it for?
It is for implementing static abilities, continuous effects, type changes, power or toughness changes, keyword grants, colour changes, and similar conditions in a card game.
Why use it?
It helps developers place these ongoing effects in the correct layer of the rules system and account for objects outside the battlefield.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/phase-rs/phase/add-static-ability
Any agent
npx skills add phase-rs/phase --skill add-static-ability
Clone the repo
git clone --depth 1 https://github.com/phase-rs/phase

Made for: Claude Code, Codex.

Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,006 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00062 $0.05006
Opus 5 $0.00031 $0.02503
Sonnet 5 $0.00012 $0.01001
Haiku 4.5 $0.00006 $0.00501

Measured 2d ago against content hash 5d884764a0a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-static-ability 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 2d 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.

.claude/skills/add-static-ability/SKILL.md · 345 lines

How it starts

The opening of the file, as written. The whole thing — 345 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Adding a Static Ability

Static abilities produce continuous effects that modify game objects through the layer system (CR 613). Unlike triggered or activated abilities, they don't use the stack — they apply continuously while their source is in the zone that ability functions in (CR 611.3b).

The affected population is OBJECTS, not permanents. CR 613.1 computes the characteristics of an object, so a static can modify a card in hand, a spell on the stack, or a card in a graveyard — not just a battlefield permanent. The layer pass does not own every zone, though: read Zone Boundary before you assume your modification will land.

Before you start: Trace how Changeling's AddAllCreatureTypes works from parser to layers. It's the best reference for type-changing effects: synthesize_changeling_cda() in synthesis.rsStaticDefinition with ContinuousModification::AddAllCreatureTypesgather_active_continuous_effects()apply_continuous_effect() in layers.rs.

CR Verification Rule: Every CR number in annotations MUST be verified by grepping docs/MagicCompRules.txt before writing. Do NOT rely on memory — 701.x and 702.x numbers are arbitrary sequential assignments that LLMs consistently hallucinate. Run grep -n "^613.1" docs/MagicCompRules.txt (etc.) for every number. If you cannot find it, do not write the annotation.


MTG Rules Reference

Rule What it governs Engine implication
613.1 Continuous effects are applied in layer order Layer enum with fixed evaluation order in evaluate_layers()
613.1a-g Layer 1-7 definitions Copy → Control → Text → Type → Color → Ability → P/T (sub-layers)
613.7 Within a layer, use timestamps (or dependency for some layers) Layers 1-4, 6, 7a-b use dependency ordering; 7c-e use timestamp ordering
604.1-3 Characteristic-defining abilities (CDAs) CDAs function in ALL zones, evaluated in Layer 7a (CharDef)
613.6 Dependencies between continuous effects order_with_dependencies() handles this for applicable layers

Read the full file on GitHub · 345 lines

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. 2d ago First seen · 345 lines · 62 tokens per session scan A 5d884764a0a9

Subscribe to this mod's changes

add-static-ability is a skill published in the GitHub repository phase-rs/phase (259 stars, last pushed 2d ago), licensed Apache-2.0. It adds 62 tokens to every session and 5,006 once invoked, about $0.0003 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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