diff --git a/app/game-frontend/e2e/directoryLists.spec.ts b/app/game-frontend/e2e/directoryLists.spec.ts
index 7983a16b..43ef9e18 100644
--- a/app/game-frontend/e2e/directoryLists.spec.ts
+++ b/app/game-frontend/e2e/directoryLists.spec.ts
@@ -710,6 +710,106 @@ test('trait and injury explanations appear on pointer hover and keyboard focus',
     await page.screenshot({ path: testInfo.outputPath('directory-trait-injury-tooltips.png'), fullPage: true });
 });
 
+for (const width of [1200, 500]) {
+    test(`catalog description line breaks stay safe on hover and focus at ${width}px`, async ({ page }, testInfo) => {
+        await page.setViewportSize({ width, height: 900 });
+        const warInfo =
+            '[계략] 화계·탈취·파괴·선동 : 성공률 +10%p<br>[전투] 계략 시도 확률 +20%p, 계략 성공 확률 +20%p';
+        const literalMarkup = '<img src=x onerror="alert(1)"><b>설명</b>';
+        const directoryRows = generals.map((general) =>
+            general.id === 10
+                ? {
+                      ...general,
+                      specialDomestic: {
+                          ...general.specialDomestic,
+                          info: `상업 특기<br/>수익 증가<BR />매매 효율\r\n${literalMarkup}`,
+                      },
+                      specialWar: { key: 'che_신산', name: '신산', info: warInfo },
+                  }
+                : general
+        );
+        await install(page, 'general', [], [], directoryRows);
+        await page.goto('general-list');
+        await page.reload();
+        const prefix = width <= 600 ? 'card-' : '';
+        const container = page
+            .locator(width <= 600 ? '[data-general-card-id="10"]' : 'tr[data-general-id="10"]')
+            .first();
+        await expect(container).toBeVisible();
+        await expect(page.getByRole('button', { name: '갱 신' })).not.toHaveAttribute('aria-busy');
+        await page.evaluate(async () => {
+            await document.fonts.ready;
+            await Promise.all(Array.from(document.images, (image) => image.decode().catch(() => undefined)));
+        });
+        const before = await container.boundingBox();
+        const evidence: Record<string, unknown> = { width, url: page.url(), before };
+        for (const [kind, expected] of [
+            ['special-domestic', ['상업 특기', '수익 증가', '매매 효율', literalMarkup]],
+            ['special-war', warInfo.split('<br>')],
+        ] as const) {
+            const trigger = page.locator(`[data-directory-tooltip="${prefix}${kind}-10"]`);
+            const tooltip = trigger.getByRole('tooltip');
+            await page.mouse.move(0, 0);
+            await trigger.hover();
+            await expect(tooltip).toBeVisible();
+            await trigger.focus();
+            await expect(tooltip).toBeVisible();
+            await expect(trigger).toHaveCSS('text-decoration-line', 'none');
+            await expect(trigger).toHaveCSS('outline-style', 'solid');
+            const description = tooltip.locator('.directory-tooltip__description');
+            await expect(description.locator('br')).toHaveCount(expected.length - 1);
+            await expect(description.locator('img, b, script')).toHaveCount(0);
+            expect(await description.innerText()).not.toMatch(/<br\s*\/?\s*>/iu);
+            const metrics = await description.evaluate((element) => {
+                const lines = Array.from(element.childNodes).filter(
+                    (node) => node.nodeType === Node.TEXT_NODE && node.textContent?.trim()
+                );
+                return {
+                    lines: lines.map((node) => {
+                        const range = document.createRange();
+                        range.selectNodeContents(node);
+                        return { text: node.textContent?.trim(), top: range.getBoundingClientRect().top };
+                    }),
+                    html: element.outerHTML,
+                };
+            });
+            expect(metrics.lines.map((line) => line.text)).toEqual(expected);
+            for (let index = 1; index < metrics.lines.length; index += 1) {
+                expect(metrics.lines[index]!.top).toBeGreaterThan(metrics.lines[index - 1]!.top);
+            }
+            const geometry = await tooltip.evaluate((element) => {
+                const rect = element.getBoundingClientRect();
+                const style = getComputedStyle(element);
+                return {
+                    left: rect.left,
+                    right: rect.right,
+                    top: rect.top,
+                    bottom: rect.bottom,
+                    font: style.font,
+                    background: style.backgroundColor,
+                    position: style.position,
+                };
+            });
+            expect(geometry.left).toBeGreaterThanOrEqual(8);
+            expect(geometry.right).toBeLessThanOrEqual(width - 8);
+            expect(geometry.top).toBeGreaterThanOrEqual(0);
+            expect(geometry.bottom).toBeLessThanOrEqual(900);
+            expect(await container.boundingBox()).toEqual(before);
+            evidence[kind] = { ...metrics, geometry };
+            await page.screenshot({ path: testInfo.outputPath(`catalog-${kind}-${width}.png`), fullPage: true });
+            await trigger.blur();
+        }
+        const empty = page.locator(`[data-directory-tooltip="${prefix}special-war-20"]`);
+        await expect(empty).not.toHaveAttribute('tabindex');
+        await expect(empty.getByRole('tooltip')).toHaveCount(0);
+        await writeFile(testInfo.outputPath('catalog-description.json'), JSON.stringify(evidence, null, 2));
+        await writeFile(
+            testInfo.outputPath('catalog-description.html'),
+            await page.locator('main').evaluate((element) => element.outerHTML)
+        );
+    });
+}
+
 test('npc directory reuses the dark sort controls and sorts from a table header', async ({ page }, testInfo) => {
     await install(page);
     await page.goto('npc-list');
diff --git a/app/game-frontend/src/components/directory/DirectoryTooltip.vue b/app/game-frontend/src/components/directory/DirectoryTooltip.vue
index 2c3f1b84..0d5b2859 100644
--- a/app/game-frontend/src/components/directory/DirectoryTooltip.vue
+++ b/app/game-frontend/src/components/directory/DirectoryTooltip.vue
@@ -1,9 +1,14 @@
 <script setup lang="ts">
-defineProps<{
+import { computed } from 'vue';
+import { splitLegacyLineBreaks } from '../../utils/legacyDescription';
+
+const props = defineProps<{
     title: string;
     description?: string | null;
     testId?: string;
 }>();
+
+const descriptionLines = computed(() => splitLegacyLineBreaks(props.description ?? ''));
 </script>
 
 <template>
@@ -16,7 +21,10 @@ defineProps<{
         <slot />
         <span v-if="description" class="directory-tooltip__content" role="tooltip">
             <strong>{{ title }}</strong>
-            <span>{{ description }}</span>
+            <span class="directory-tooltip__description"
+                ><template v-for="(line, index) in descriptionLines" :key="index"
+                    >{{ line }}<br v-if="index < descriptionLines.length - 1" /></template
+            ></span>
         </span>
     </span>
 </template>
diff --git a/app/game-frontend/src/components/ui/RichTooltip.vue b/app/game-frontend/src/components/ui/RichTooltip.vue
index 3669be41..b4350f77 100644
--- a/app/game-frontend/src/components/ui/RichTooltip.vue
+++ b/app/game-frontend/src/components/ui/RichTooltip.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import { computed, nextTick, onBeforeUnmount, onMounted, ref, useSlots, watch } from 'vue';
+import { splitLegacyLineBreaks } from '../../utils/legacyDescription';
 import tippy, { type Instance, type Placement } from 'tippy.js';
 import 'tippy.js/dist/tippy.css';
 
@@ -28,7 +29,7 @@ let instance: Instance | null = null;
 const descriptionLines = computed(() => {
     const source = Array.isArray(props.description) ? props.description : [props.description ?? ''];
     return source
-        .flatMap((line) => line.split(/<br\s*\/?\s*>|\r?\n/giu))
+        .flatMap(splitLegacyLineBreaks)
         .map((line) => line.trim())
         .filter(Boolean);
 });
diff --git a/app/game-frontend/src/utils/legacyDescription.ts b/app/game-frontend/src/utils/legacyDescription.ts
new file mode 100644
index 00000000..a661f54e
--- /dev/null
+++ b/app/game-frontend/src/utils/legacyDescription.ts
@@ -0,0 +1,5 @@
+/**
+ * 카탈로그 설명의 Ref 줄바꿈만 해석한다. 반환값은 반드시 text interpolation으로
+ * 렌더링하며 HTML로 삽입하지 않는다. 빈 줄과 공백의 표시 정책은 소비자가 정한다.
+ */
+export const splitLegacyLineBreaks = (value: string): string[] => value.split(/<br\s*\/?\s*>|\r\n?|\n/giu);
diff --git a/app/game-frontend/src/views/InheritView.vue b/app/game-frontend/src/views/InheritView.vue
index b69be132..40d7989d 100644
--- a/app/game-frontend/src/views/InheritView.vue
+++ b/app/game-frontend/src/views/InheritView.vue
@@ -4,6 +4,7 @@ import { usePageExit } from '../composables/usePageExit';
 import { formatServerDateTime } from '@sammo-ts/common/time/ServerDateTime';
 import { JosaUtil } from '@sammo-ts/common/util/JosaUtil';
 import { computed, onMounted, reactive, ref } from 'vue';
+import { splitLegacyLineBreaks } from '../utils/legacyDescription';
 import { trpc } from '../utils/trpc';
 import { useGameFeedback } from '../composables/useGameFeedback';
 
@@ -207,7 +208,6 @@ const specialNameMap = computed(() => {
     }
     return map;
 });
-const splitLegacyLineBreaks = (value: string): string[] => value.split(/<br\s*\/?\s*>|\r?\n/giu);
 const selectedSpecialWarInfo = computed(
     () => status.value?.availableSpecialWar.find((entry) => entry.key === nextSpecialKey.value)?.info ?? ''
 );
diff --git a/app/game-frontend/test/legacyDescription.test.ts b/app/game-frontend/test/legacyDescription.test.ts
new file mode 100644
index 00000000..56b09c8f
--- /dev/null
+++ b/app/game-frontend/test/legacyDescription.test.ts
@@ -0,0 +1,28 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import { splitLegacyLineBreaks } from '../src/utils/legacyDescription.ts';
+
+void describe('legacy catalog description line breaks', () => {
+    void it('accepts catalog br variants and platform newlines', () => {
+        assert.deepEqual(splitLegacyLineBreaks('가<br>나<BR/>다<br />라\r\n마\n바\r사'), [
+            '가',
+            '나',
+            '다',
+            '라',
+            '마',
+            '바',
+            '사',
+        ]);
+    });
+
+    void it('preserves empty lines, whitespace, and unformatted descriptions', () => {
+        assert.deepEqual(splitLegacyLineBreaks(''), ['']);
+        assert.deepEqual(splitLegacyLineBreaks(' 일반 설명 '), [' 일반 설명 ']);
+        assert.deepEqual(splitLegacyLineBreaks('<br>첫 줄<br><br>끝 줄\n'), ['', '첫 줄', '', '끝 줄', '']);
+    });
+
+    void it('leaves other markup, attributes, and entities as literal text', () => {
+        const text = '<img src=x onerror="alert(1)"><b>문구</b>&lt;br&gt;<br onclick="alert(1)">';
+        assert.deepEqual(splitLegacyLineBreaks(text), [text]);
+    });
+});
diff --git a/docs/frontend-css-architecture.md b/docs/frontend-css-architecture.md
index 42db7325..bb2db333 100644
--- a/docs/frontend-css-architecture.md
+++ b/docs/frontend-css-architecture.md
@@ -41,6 +41,14 @@ tooltip trigger는 hover/focus 동작과 `cursor: help`를 유지하되, tooltip
 텍스트에 점선 밑줄을 반복하지 않습니다. keyboard `focus-visible` outline은 별도의
 접근성 상태로 유지합니다.
 
+카탈로그 설명의 줄바꿈은 `src/utils/legacyDescription.ts`의
+`splitLegacyLineBreaks()`가 해석합니다. `DirectoryTooltip`, `RichTooltip`, 유산의
+특기·유니크 설명은 `<br>`, `<br/>`, `<br />`(대소문자 무관)와 실제 개행을 이 함수로
+나누고 각 줄을 Vue text interpolation으로 렌더링합니다. 다른 HTML이나 entity는
+텍스트로 유지합니다. 일람·유산은 빈 줄을 보존하며, `RichTooltip`은 기존대로 각 줄의
+앞뒤 공백과 빈 줄을 제거합니다. 일람의 표와 모바일 카드에는 같은 tooltip을 쓰며
+줄바꿈 때문에 trigger의 geometry나 많은 행을 위한 lazy 구조를 바꾸지 않습니다.
+
 ## Button composition
 
 Choose the Ref visual family before choosing a semantic color. Buttons from