diff --git a/TODO.md b/TODO.md
index d183187..9f81124 100644
--- a/TODO.md
+++ b/TODO.md
@@ -5,7 +5,6 @@
 
 ## Minor Gameplay Polish
 
-- [ ] **More detailed card tooltips.** Currently cards have a tooltip that show what they represent when played on obstacles, but they don't show what they represent *as* obstacles, which is relevant when issuing challenges to other Pi-Rats.
 - [ ] **Add invite link to Admin panel**
 - [ ] **Add crew/player/rat name to page title, if available**. This will make it easier to distinguish tabs/browser history entries
 - [ ] **Save active sessions in browser local storage**. Whenever you create or join a game, your browser local storage should be updated with the game ID, player ID, crew name, and player/rat names (if available). Going to the home page with saved sessions should provide a menu of games to rejoin in addition to the ability to start a new game. It should be possible to delete entries from this list, which only affects the browser local storage, not the backend database, and is undoable (the entry doesn't disappear immediately, it's just marked as deleted until page refresh).
diff --git a/frontend/src/components/Card.svelte b/frontend/src/components/Card.svelte
index c879341..93c7f55 100644
--- a/frontend/src/components/Card.svelte
+++ b/frontend/src/components/Card.svelte
@@ -1,5 +1,5 @@
 <script>
-    import { SUIT_EMOJI, isJoker, cardValue, cardSuit, cardTooltip } from '../lib/cards';
+    import { SUIT_EMOJI, isJoker, cardValue, cardSuit, cardTooltip, obstacleTable } from '../lib/cards';
 
     export let card;            // card code, e.g. "10D" or "Joker1"
     export let size = 'large';  // 'large' | 'medium' | 'mini'
@@ -16,8 +16,9 @@
     $: suit = joker ? '' : SUIT_EMOJI[cardSuit(card)];
     $: suitClass = joker ? 'joker' : cardSuit(card).toLowerCase();
     $: techName = techs && !joker ? techs[cardValue(card)] : null;
-    // Tooltip: explicit title wins; otherwise remind the player of the suit's theme
-    $: tooltip = title || cardTooltip(card);
+    // Tooltip: explicit title wins; otherwise the suit's theme plus what the
+    // card would represent as an Obstacle (recomputes once the table loads)
+    $: tooltip = title || cardTooltip(card, $obstacleTable);
 </script>
 
 {#if size === 'mini'}
diff --git a/frontend/src/components/scene/ChallengePanel.svelte b/frontend/src/components/scene/ChallengePanel.svelte
index c31b95c..17afa53 100644
--- a/frontend/src/components/scene/ChallengePanel.svelte
+++ b/frontend/src/components/scene/ChallengePanel.svelte
@@ -1,6 +1,6 @@
 <script>
     import { apiRequest } from '../../lib/api';
-    import { getCardDisplay, isJoker, displayName, playerName as lookupName } from '../../lib/cards';
+    import { getCardDisplay, isJoker, displayName, playerName as lookupName, cardTooltip, obstacleTable } from '../../lib/cards';
 
     export let state;
 
@@ -83,7 +83,7 @@
         {/if}
         {#if ch.challenge_type === 'pvp'}
             <p class="info-text" style="margin: 0.5rem 0 0 0;">
-                Temporary Obstacle: <strong>{getCardDisplay(ch.temp_card)}</strong> — {playerName(ch.acting_player_id)} must answer it!
+                Temporary Obstacle: <strong title={cardTooltip(ch.temp_card, $obstacleTable)}>{getCardDisplay(ch.temp_card)}</strong> — {playerName(ch.acting_player_id)} must answer it!
             </p>
         {:else}
             <p class="info-text" style="margin: 0.5rem 0 0 0;">
@@ -134,7 +134,7 @@
                 <p style="margin: 0 0 0.5rem 0;"><strong>Defend yourself!</strong> Pick a card:</p>
                 <div class="challenge-actions">
                     {#each hand.filter(c => !isJoker(c)) as card}
-                        <button class="btn btn-secondary" on:click={() => pvpDefend(ch.id, card)}>{getCardDisplay(card)}</button>
+                        <button class="btn btn-secondary" title={cardTooltip(card, $obstacleTable)} on:click={() => pvpDefend(ch.id, card)}>{getCardDisplay(card)}</button>
                     {/each}
                 </div>
             </div>
diff --git a/frontend/src/components/scene/CharacterSheet.svelte b/frontend/src/components/scene/CharacterSheet.svelte
index b191b7f..15f718b 100644
--- a/frontend/src/components/scene/CharacterSheet.svelte
+++ b/frontend/src/components/scene/CharacterSheet.svelte
@@ -1,6 +1,6 @@
 <script>
     import { apiRequest } from '../../lib/api';
-    import { getCardDisplay, isJoker, displayName } from '../../lib/cards';
+    import { getCardDisplay, isJoker, displayName, cardObstacleInfo, obstacleTable } from '../../lib/cards';
 
     export let state;
 
@@ -12,6 +12,8 @@
     $: hand = state.player.hand_cards ? JSON.parse(state.player.hand_cards) : [];
     $: scenePirats = state.players.filter(p => p.role === 'pirat');
     $: duelTargets = scenePirats.filter(p => p.id !== state.player.id && !p.is_dead);
+    // What the chosen duel card becomes as a temporary Obstacle for the defender
+    $: pvpCardObstacle = cardObstacleInfo(pvpCard, $obstacleTable);
 
     async function submitNewName() {
         if (!newNameInput.trim()) return;
@@ -122,9 +124,14 @@
                 <select class="select-field" bind:value={pvpCard} style="width: 100%; margin-bottom: 0.5rem;">
                     <option value="">Throw which card?</option>
                     {#each hand.filter(c => !isJoker(c)) as card}
-                        <option value={card}>{getCardDisplay(card)}</option>
+                        <option value={card} title={cardObstacleInfo(card, $obstacleTable) ? `${cardObstacleInfo(card, $obstacleTable).title} — ${cardObstacleInfo(card, $obstacleTable).description}` : ''}>{getCardDisplay(card)}</option>
                     {/each}
                 </select>
+                {#if pvpCardObstacle}
+                    <p class="info-text" style="font-size: 0.8rem; margin: -0.25rem 0 0.5rem 0;">
+                        As an Obstacle, {getCardDisplay(pvpCard)} is <strong>{pvpCardObstacle.title}</strong>: {pvpCardObstacle.description}
+                    </p>
+                {/if}
                 <button class="btn btn-secondary btn-full" on:click={createPvp} disabled={!pvpOpponentId || !pvpCard}>Throw Down!</button>
             </div>
         {/if}
diff --git a/frontend/src/lib/cards.js b/frontend/src/lib/cards.js
index 77e5911..92b9403 100644
--- a/frontend/src/lib/cards.js
+++ b/frontend/src/lib/cards.js
@@ -1,5 +1,8 @@
 // Card-code helpers shared across components.
 // Codes look like "10D", "KH", "Joker1" (black) / "Joker2" (red).
+import { writable } from 'svelte/store';
+import { apiRequest } from './api';
+
 export const SUIT_EMOJI = { C: '♣️', S: '♠️', H: '♥️', D: '♦️' };
 
 // Suit themes from the rulebook: how a Pi-Rat overcomes an Obstacle with that suit.
@@ -10,11 +13,49 @@ export const SUIT_THEMES = {
     H: "♥ Hearts — Shoutin' and Singin': social skills, performance, or charisma",
 };
 
-// Default tooltip for a card: its suit theme (or what a Joker does).
-export function cardTooltip(code) {
+// The rulebook's obstacle tables (what each card represents when it surfaces
+// as an Obstacle), served by the backend so there's a single source of truth.
+// Loaded once at startup; until it arrives tooltips fall back to suit themes.
+let OBSTACLE_TABLE = null;
+export const obstacleTable = writable(null);
+export async function loadObstacleTable(retries = 5) {
+    // Static rulebook data; retry on transient failures so a single blip on
+    // first load doesn't silently disable obstacle tooltips until a refresh.
+    while (!OBSTACLE_TABLE && retries-- > 0) {
+        try {
+            OBSTACLE_TABLE = (await apiRequest('/obstacles')).obstacles;
+            obstacleTable.set(OBSTACLE_TABLE);
+        } catch (e) {
+            if (retries <= 0) {
+                console.error('Failed to load obstacle table', e);
+            } else {
+                await new Promise(r => setTimeout(r, 1000));
+            }
+        }
+    }
+    return OBSTACLE_TABLE;
+}
+
+// What a card represents when it surfaces as an Obstacle, or null if unknown
+// (Jokers / table not loaded). Pass the obstacleTable store value as `table`.
+export function cardObstacleInfo(code, table = OBSTACLE_TABLE) {
+    if (!code || isJoker(code)) return null;
+    return table?.[cardSuit(code)]?.[cardValue(code)] || null;
+}
+
+// Default tooltip for a card: its suit theme when played, plus what it
+// represents as an Obstacle (relevant when challenging another Pi-Rat).
+// Pass the obstacleTable store's value as `table` to recompute reactively.
+export function cardTooltip(code, table = OBSTACLE_TABLE) {
     if (!code) return '';
-    if (isJoker(code)) return '🃏 Joker — discards an Obstacle outright and draws a replacement';
-    return SUIT_THEMES[cardSuit(code)] || '';
+    if (isJoker(code)) {
+        return '🃏 Joker — played: discards an Obstacle (and its column) outright and draws a replacement.\n'
+            + 'As an Obstacle: discarded, but future scenes permanently require one more Obstacle.';
+    }
+    const theme = SUIT_THEMES[cardSuit(code)] || '';
+    const obstacle = table?.[cardSuit(code)]?.[cardValue(code)];
+    if (!obstacle) return theme;
+    return `${theme}\nAs an Obstacle: ${obstacle.title} — ${obstacle.description}`;
 }
 
 export function isJoker(code) {
diff --git a/frontend/src/main.js b/frontend/src/main.js
index 6ec74cb..f4ac104 100644
--- a/frontend/src/main.js
+++ b/frontend/src/main.js
@@ -10,6 +10,10 @@ import '@fontsource/alegreya-sans/700.css'
 
 import './app.css'
 import App from './App.svelte'
+import { loadObstacleTable } from './lib/cards'
+
+// Warm the obstacle-table cache so card tooltips can describe cards as Obstacles
+loadObstacleTable()
 
 const app = mount(App, {
   target: document.getElementById('app'),
diff --git a/src/pirats/routes_scene.py b/src/pirats/routes_scene.py
index 2491225..0ee1f05 100644
--- a/src/pirats/routes_scene.py
+++ b/src/pirats/routes_scene.py
@@ -3,9 +3,21 @@ from fastapi.responses import JSONResponse
 from sqlmodel import Session
 from .database import get_session
 from . import crud
+from .cards import OBSTACLES_DATA
 
 router = APIRouter()
 
+# The rulebook's obstacle tables: what every card represents when drawn as an
+# Obstacle (used by the frontend for card tooltips)
+@router.get("/obstacles")
+def obstacle_table():
+    return {
+        "obstacles": {
+            suit: {val: {"title": t, "description": d} for val, (t, d) in table.items()}
+            for suit, table in OBSTACLES_DATA.items()
+        }
+    }
+
 # Set Role during Scene Setup
 @router.post("/game/{game_id}/player/{player_id}/set-role")
 def player_set_role(