diff --git a/AGENTS.md b/AGENTS.md
index 0039c62faa..1cbac6ff33 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -1,6 +1,6 @@
 # Everything Claude Code (ECC) — Agent Instructions
 
-This is a **production-ready AI coding plugin** providing 27 specialized agents, 114 skills, 59 commands, and automated hook workflows for software development.
+This is a **production-ready AI coding plugin** providing 27 specialized agents, 113 skills, 58 commands, and automated hook workflows for software development.
 
 **Version:** 1.9.0
 
@@ -142,8 +142,8 @@ Troubleshoot failures: check test isolation → verify mocks → fix implementat
 
 ```
 agents/          — 27 specialized subagents
-skills/          — 114 workflow skills and domain knowledge
-commands/        — 59 slash commands
+skills/          — 109 workflow skills and domain knowledge
+commands/        — 58 slash commands
 hooks/           — Trigger-based automations
 rules/           — Always-follow guidelines (common + per-language)
 scripts/         — Cross-platform Node.js utilities
diff --git a/docs/ja-JP/skills/configure-ecc/SKILL.md b/docs/ja-JP/skills/configure-ecc/SKILL.md
index 0a9ba790bd..6c4a5edd23 100644
--- a/docs/ja-JP/skills/configure-ecc/SKILL.md
+++ b/docs/ja-JP/skills/configure-ecc/SKILL.md
@@ -157,10 +157,11 @@ Options:
 # 共通ルール（rules/ にフラットコピー）
 cp -r $ECC_ROOT/rules/common/* $TARGET/rules/
 
-# 言語固有のルール（rules/ にフラットコピー）
-cp -r $ECC_ROOT/rules/typescript/* $TARGET/rules/   # 選択された場合
-cp -r $ECC_ROOT/rules/python/* $TARGET/rules/        # 選択された場合
-cp -r $ECC_ROOT/rules/golang/* $TARGET/rules/        # 選択された場合
+# 言語固有のルール（共通ルールの上書きを防ぐためプレフィックス付き）
+# coding-style.md は typescript-coding-style.md のようになります
+for f in "$ECC_ROOT"/rules/typescript/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/typescript-$(basename "$f")"; done   # 選択された場合
+for f in "$ECC_ROOT"/rules/python/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/python-$(basename "$f")"; done           # 選択された場合
+for f in "$ECC_ROOT"/rules/golang/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/golang-$(basename "$f")"; done           # 選択された場合
 ```
 
 **重要**: ユーザーが言語固有のルールを選択したが、共通ルールを選択しなかった場合、警告します：
diff --git a/docs/zh-CN/skills/configure-ecc/SKILL.md b/docs/zh-CN/skills/configure-ecc/SKILL.md
index e45d8f8518..caf6f4a5f4 100644
--- a/docs/zh-CN/skills/configure-ecc/SKILL.md
+++ b/docs/zh-CN/skills/configure-ecc/SKILL.md
@@ -224,10 +224,11 @@ Options:
 # Common rules (flat copy into rules/)
 cp -r $ECC_ROOT/rules/common/* $TARGET/rules/
 
-# Language-specific rules (flat copy into rules/)
-cp -r $ECC_ROOT/rules/typescript/* $TARGET/rules/   # if selected
-cp -r $ECC_ROOT/rules/python/* $TARGET/rules/        # if selected
-cp -r $ECC_ROOT/rules/golang/* $TARGET/rules/        # if selected
+# Language-specific rules (prefixed to avoid overwriting common rules)
+# Files like coding-style.md become typescript-coding-style.md, etc.
+for f in "$ECC_ROOT"/rules/typescript/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/typescript-$(basename "$f")"; done   # if selected
+for f in "$ECC_ROOT"/rules/python/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/python-$(basename "$f")"; done           # if selected
+for f in "$ECC_ROOT"/rules/golang/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/golang-$(basename "$f")"; done           # if selected
 ```
 
 **重要**：如果用户选择了任何特定语言的规则但**没有**选择通用规则，警告他们：
diff --git a/skills/configure-ecc/SKILL.md b/skills/configure-ecc/SKILL.md
index 07109a30e0..c11445ef45 100644
--- a/skills/configure-ecc/SKILL.md
+++ b/skills/configure-ecc/SKILL.md
@@ -221,10 +221,11 @@ Execute installation:
 # Common rules (flat copy into rules/)
 cp -r $ECC_ROOT/rules/common/* $TARGET/rules/
 
-# Language-specific rules (flat copy into rules/)
-cp -r $ECC_ROOT/rules/typescript/* $TARGET/rules/   # if selected
-cp -r $ECC_ROOT/rules/python/* $TARGET/rules/        # if selected
-cp -r $ECC_ROOT/rules/golang/* $TARGET/rules/        # if selected
+# Language-specific rules (prefixed to avoid overwriting common rules)
+# Files like coding-style.md become typescript-coding-style.md, etc.
+for f in "$ECC_ROOT"/rules/typescript/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/typescript-$(basename "$f")"; done   # if selected
+for f in "$ECC_ROOT"/rules/python/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/python-$(basename "$f")"; done           # if selected
+for f in "$ECC_ROOT"/rules/golang/*; do [ -e "$f" ] && cp -r "$f" "$TARGET/rules/golang-$(basename "$f")"; done           # if selected
 ```
 
 **Important**: If the user selects any language-specific rules but NOT common rules, warn them:
@@ -360,6 +361,7 @@ Then print a summary report:
 
 ### "Rules not working"
 - Rules are flat files, not in subdirectories: `$TARGET/rules/coding-style.md` (correct) vs `$TARGET/rules/common/coding-style.md` (incorrect for flat install)
+- Language-specific rules are prefixed: `$TARGET/rules/python-coding-style.md` (correct) vs `$TARGET/rules/coding-style.md` (incorrect — overwrites the common rule)
 - Restart Claude Code after installing rules
 
 ### "Path reference errors after project-level install"