fix(strategy): treat opened pack cost as sunk, not refundable

CLAUDE.md

@@ -81,6 +81,10 @@ Data collection and statistics. Output: `runs/v1.0.0/{strategy}/{vendor}/{model}
 
 Template-based system using Jinja2. Templates render strategy guidance, game state, and action history into LLM prompts. At each decision point: render templates → send to LLM with tools → execute tool call. Custom strategies: create folder in `src/balatrollm/strategies/` with required template files.
 
+**Gotcha — pack card modifiers:** BalatroBot puts enhancement/edition/seal on `card.modifier.*`, never on `card.value.*` (`value` is only `suit`/`rank`/`effect`). In `GAMESTATE.md.jinja` pack sections (`SMODS_BOOSTER_OPENED`), always use `card.modifier.enhancement` / `edition` / `seal` (same as hand/shop). Reading `card.value.enhancement` renders blank lines and hides Standard-pack modifiers from the LLM.
+
+**Gotcha — pack skip is not a refund:** Buying a booster spends money immediately. In `SMODS_BOOSTER_OPENED`, skipping takes no card and does not refund the purchase. Strategy/GAMESTATE/TOOLS guidance must say the cost is already spent and prefer taking upside unless there is a skip-payoff joker (e.g. Red Card) or every option is actively harmful. Do not imply that skipping after purchase saves money.
+
 ### Relationship with BalatroBot
 
 **BalatroBot** is a Lua mod that runs inside the Balatro game and exposes a JSON-RPC 2.0 HTTP API for programmatic control.

src/balatrollm/strategies/aggressive/GAMESTATE.md.jinja

@@ -207,7 +207,7 @@ Here are the vouchers that can be redeemed:
 {% if G.state == "SMODS_BOOSTER_OPENED" -%}
 ## Pack Selection
 
-You have opened a booster pack. Choose a card or skip.
+You have opened a booster pack. The purchase cost is already spent — skipping does not refund money. Prefer selecting a card with any upside unless you have a skip-payoff joker (e.g. Red Card) or every option is actively harmful.
 
 ### Available Cards in Pack
 
@@ -222,17 +222,17 @@ You have opened a booster pack. Choose a card or skip.
 {% if card.value.min_highlighted %}  - **Targets**: {{ card.value.min_highlighted }}-{{ card.value.max_highlighted }} hand cards{% endif %}
 {% elif card.set in ["DEFAULT", "ENHANCED"] %}
 - {{ loop.index0 }}: **{{ card.value.rank }} of {{ card.value.suit }}**
-{% if card.set == "ENHANCED" %}  - **Enhancement**: {{ card.value.enhancement }}{% endif %}
-{% if card.value.edition %}  - **Edition**: {{ card.value.edition }}{% endif %}
-{% if card.value.seal %}  - **Seal**: {{ card.value.seal }}{% endif %}
+{% if card.modifier.edition %}  - **{{ card.modifier.edition }} Edition**{% endif %}
+{% if card.modifier.enhancement %}  - **{{ card.modifier.enhancement }} Enhancement**{% endif %}
+{% if card.modifier.seal %}  - **{{ card.modifier.seal }} Seal**{% endif %}
 {% endif %}
 {%- endfor %}
 
 {% if G.hand and G.hand.cards %}
 ### Your Hand (for targeting)
 
 {% for card in G.hand.cards -%}
-- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.set == "ENHANCED" %} ({{ card.value.enhancement }}){% endif %}
+- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.modifier.enhancement %} ({{ card.modifier.enhancement }}){% endif %}
 {% endfor %}
 {% endif %}
 {%- endif %}

src/balatrollm/strategies/aggressive/STRATEGY.md.jinja

@@ -107,6 +107,11 @@ The shop sells: 2 random cards (usually Jokers), 1 Voucher, 2 Booster Packs.
 - **Buffoon Packs**: Joker Cards to add to your run
 - **Spectral Packs**: Spectral Cards for immediate use (HIGH RISK/HIGH REWARD)
 
+**After buying a pack (sunk cost):**
+- The purchase cost is **already spent**. Skipping does not refund money.
+- Prefer taking any card with potential upside over skipping for "savings".
+- Skip only if: (1) you have a skip-payoff joker (e.g. Red Card), or (2) every option is actively harmful (bad Spectral, unwanted deck dilution, forcing out a better joker).
+
 ## Jokers
 
 Jokers are 150 special cards that modify scoring. Every run starts with 5 empty Joker slots. Jokers are ESSENTIAL for defeating higher antes.

src/balatrollm/strategies/aggressive/TOOLS.json

@@ -326,7 +326,7 @@
       "function": {
         "name": "pack",
         "strict": false,
-        "description": "Select a card from the opened booster pack, or skip without taking any card. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards.",
+        "description": "Select a card from the opened booster pack, or skip without taking any card. The pack cost is already spent — skipping does not refund money. Prefer taking a useful card unless you have a skip-payoff joker or every option is harmful. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards.",
         "parameters": {
           "type": "object",
           "properties": {

src/balatrollm/strategies/conservative/GAMESTATE.md.jinja

@@ -208,7 +208,7 @@ Here are the vouchers that can be redeemed:
 {% if G.state == "SMODS_BOOSTER_OPENED" -%}
 ## Pack Selection
 
-You have opened a booster pack. Choose a card or skip.
+You have opened a booster pack. The purchase cost is already spent — skipping does not refund money. Prefer selecting a card with any upside unless you have a skip-payoff joker (e.g. Red Card) or every option is actively harmful.
 
 ### Available Cards in Pack
 
@@ -223,17 +223,17 @@ You have opened a booster pack. Choose a card or skip.
 {% if card.value.min_highlighted %}  - **Targets**: {{ card.value.min_highlighted }}-{{ card.value.max_highlighted }} hand cards{% endif %}
 {% elif card.set in ["DEFAULT", "ENHANCED"] %}
 - {{ loop.index0 }}: **{{ card.value.rank }} of {{ card.value.suit }}**
-{% if card.set == "ENHANCED" %}  - **Enhancement**: {{ card.value.enhancement }}{% if card.value.enhancement == "GLASS" %} ⚠️ RISKY{% endif %}{% endif %}
-{% if card.value.edition %}  - **Edition**: {{ card.value.edition }}{% endif %}
-{% if card.value.seal %}  - **Seal**: {{ card.value.seal }}{% endif %}
+{% if card.modifier.edition %}  - **{{ card.modifier.edition }} Edition**{% endif %}
+{% if card.modifier.enhancement %}  - **{{ card.modifier.enhancement }} Enhancement**{% if card.modifier.enhancement == "GLASS" %} ⚠️ RISKY{% endif %}{% endif %}
+{% if card.modifier.seal %}  - **{{ card.modifier.seal }} Seal**{% endif %}
 {% endif %}
 {%- endfor %}
 
 {% if G.hand and G.hand.cards %}
 ### Your Hand (for targeting)
 
 {% for card in G.hand.cards -%}
-- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.set == "ENHANCED" %} ({{ card.value.enhancement }}){% endif %}
+- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.modifier.enhancement %} ({{ card.modifier.enhancement }}){% endif %}
 {% endfor %}
 {% endif %}
 {%- endif %}

src/balatrollm/strategies/conservative/STRATEGY.md.jinja

@@ -179,6 +179,11 @@ Each shop visit offers:
 
 **Conservative Pack Priority**: Celestial > Arcana > Buffoon > Standard >>> Spectral
 
+**After buying a pack (sunk cost):**
+- The purchase cost is **already spent**. Skipping does not refund money.
+- Prefer taking any card with potential upside over skipping for "savings".
+- Skip only if: (1) you have a skip-payoff joker (e.g. Red Card), or (2) every option is actively harmful (bad Spectral, unwanted deck dilution, forcing out a better joker).
+
 ### Economy Rules
 
 - **Interest**: Earn $1 per $5 held, maximum $5 interest (at $25+)

src/balatrollm/strategies/conservative/TOOLS.json

@@ -326,7 +326,7 @@
       "function": {
         "name": "pack",
         "strict": false,
-        "description": "Select a card from the opened booster pack, or skip without taking any card. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards. Avoid risky Spectral cards.",
+        "description": "Select a card from the opened booster pack, or skip without taking any card. The pack cost is already spent — skipping does not refund money. Prefer taking a useful card unless you have a skip-payoff joker or every option is harmful. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards. Avoid risky Spectral cards.",
         "parameters": {
           "type": "object",
           "properties": {

src/balatrollm/strategies/default/GAMESTATE.md.jinja

@@ -207,7 +207,7 @@ Here are the vouchers that can be redeemed:
 {% if G.state == "SMODS_BOOSTER_OPENED" -%}
 ## Pack Selection
 
-You have opened a booster pack. Choose a card or skip.
+You have opened a booster pack. The purchase cost is already spent — skipping does not refund money. Prefer selecting a card with any upside unless you have a skip-payoff joker (e.g. Red Card) or every option is actively harmful.
 
 ### Available Cards in Pack
 
@@ -222,17 +222,17 @@ You have opened a booster pack. Choose a card or skip.
 {% if card.value.min_highlighted %}  - **Targets**: {{ card.value.min_highlighted }}-{{ card.value.max_highlighted }} hand cards{% endif %}
 {% elif card.set in ["DEFAULT", "ENHANCED"] %}
 - {{ loop.index0 }}: **{{ card.value.rank }} of {{ card.value.suit }}**
-{% if card.set == "ENHANCED" %}  - **Enhancement**: {{ card.value.enhancement }}{% endif %}
-{% if card.value.edition %}  - **Edition**: {{ card.value.edition }}{% endif %}
-{% if card.value.seal %}  - **Seal**: {{ card.value.seal }}{% endif %}
+{% if card.modifier.edition %}  - **{{ card.modifier.edition }} Edition**{% endif %}
+{% if card.modifier.enhancement %}  - **{{ card.modifier.enhancement }} Enhancement**{% endif %}
+{% if card.modifier.seal %}  - **{{ card.modifier.seal }} Seal**{% endif %}
 {% endif %}
 {%- endfor %}
 
 {% if G.hand and G.hand.cards %}
 ### Your Hand (for targeting)
 
 {% for card in G.hand.cards -%}
-- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.set == "ENHANCED" %} ({{ card.value.enhancement }}){% endif %}
+- {{ loop.index0 }}: {{ card.value.rank }} of {{ card.value.suit }}{% if card.modifier.enhancement %} ({{ card.modifier.enhancement }}){% endif %}
 {% endfor %}
 {% endif %}
 {%- endif %}

src/balatrollm/strategies/default/STRATEGY.md.jinja

@@ -232,9 +232,13 @@ Booster packs provide valuable cards but use them wisely:
 **Pack Selection Tips:**
 - For Arcana/Spectral packs, cards are used **immediately**
 - Some cards (like The Magician) require selecting target cards from your hand
-- Consider skipping if no cards benefit your current strategy
 - Buffoon/Standard packs add cards to your collection (not used immediately)
 
+**After buying a pack (sunk cost):**
+- The purchase cost is **already spent**. Skipping does not refund money.
+- Prefer taking any card with potential upside over skipping for "savings".
+- Skip only if: (1) you have a skip-payoff joker (e.g. Red Card), or (2) every option is actively harmful (bad Spectral, unwanted deck dilution, forcing out a better joker).
+
 **Targeting for Tarot/Spectral:**
 When a card requires targets:
 - Check the card's effect for how many cards to select

src/balatrollm/strategies/default/TOOLS.json

@@ -326,7 +326,7 @@
       "function": {
         "name": "pack",
         "strict": false,
-        "description": "Select a card from the opened booster pack, or skip without taking any card. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards.",
+        "description": "Select a card from the opened booster pack, or skip without taking any card. The pack cost is already spent — skipping does not refund money. Prefer taking a useful card unless you have a skip-payoff joker or every option is harmful. For Arcana/Spectral packs, cards are used immediately and may require targeting hand cards.",
         "parameters": {
           "type": "object",
           "properties": {

tests/unit/test_strategy.py

@@ -1,11 +1,80 @@
 """Unit tests for the StrategyManager module."""
 
+from typing import Any
+
 import pytest
 
 from balatrollm.strategy import StrategyManager
 from tests.unit.conftest import load_unit_fixture, load_unit_golden
 
 
+def get_mock_pack_playing_card(
+    overrides: dict[str, object] | None = None,
+) -> dict[str, Any]:
+    """Factory for a pack playing card shaped like BalatroBot gamestate."""
+    base: dict[str, Any] = {
+        "id": 1,
+        "key": "D_6",
+        "set": "ENHANCED",
+        "label": "Glass Card",
+        "value": {
+            "rank": "6",
+            "suit": "D",
+            "effect": "+6 chips X2 Mult 1 in 4 chance to destroy card",
+        },
+        "modifier": {
+            "enhancement": "GLASS",
+            "edition": "FOIL",
+            "seal": "RED",
+        },
+        "state": {},
+        "cost": {"buy": 1, "sell": 1},
+    }
+    return {**base, **(overrides or {})}
+
+
+def get_mock_pack_opened_gamestate(
+    overrides: dict[str, object] | None = None,
+) -> dict[str, Any]:
+    """Factory for SMODS_BOOSTER_OPENED gamestate with pack playing cards."""
+    base: dict[str, Any] = {
+        "state": "SMODS_BOOSTER_OPENED",
+        "money": 10,
+        "ante_num": 1,
+        "round_num": 1,
+        "deck": "RED",
+        "stake": "WHITE",
+        "seed": "AAAAAAA",
+        "won": False,
+        "round": {
+            "hands_left": 4,
+            "discards_left": 3,
+            "hands_played": 0,
+            "discards_used": 0,
+            "chips": 0,
+            "reroll_cost": 5,
+        },
+        "jokers": {"count": 0, "limit": 5, "cards": []},
+        "consumables": {"count": 0, "limit": 2, "cards": []},
+        "hand": {"count": 0, "limit": 8, "cards": [], "highlighted_limit": 5},
+        "shop": {"count": 0, "limit": 2, "cards": []},
+        "packs": {"count": 0, "limit": 2, "cards": []},
+        "vouchers": {"count": 0, "limit": 1, "cards": []},
+        "pack": {
+            "count": 1,
+            "limit": 3,
+            "cards": [get_mock_pack_playing_card()],
+        },
+        "hands": {},
+        "blinds": {
+            "small": {"name": "Small Blind", "score": 300, "status": "Upcoming"},
+            "big": {"name": "Big Blind", "score": 450, "status": "Upcoming"},
+            "boss": {"name": "The Hook", "score": 600, "status": "Upcoming"},
+        },
+    }
+    return {**base, **(overrides or {})}
+
+
 class TestStrategyManagerInit:
     """Tests for StrategyManager initialization."""
 
@@ -184,6 +253,86 @@ def test_blinds_rendered_in_blind_select(self) -> None:
             assert str(blind["score"]) in result, f"{blind_type} blind score not found"
 
 
+class TestPackOpenSunkCostGuidance:
+    """Opened packs already spent money; skip is not a refund."""
+
+    @pytest.mark.parametrize("strategy", ["default", "conservative", "aggressive"])
+    def test_strategy_teaches_pack_skip_does_not_refund(self, strategy: str) -> None:
+        """Strategy text must state pack cost is sunk and skip does not refund."""
+        gamestate = get_mock_pack_opened_gamestate()
+        sm = StrategyManager(strategy)
+        result = sm.render_strategy(gamestate)
+
+        assert "already spent" in result.lower()
+        assert "does not refund" in result.lower()
+
+    @pytest.mark.parametrize("strategy", ["default", "conservative", "aggressive"])
+    def test_pack_opened_gamestate_teaches_sunk_cost(self, strategy: str) -> None:
+        """Pack-open gamestate must remind the LLM money is already spent."""
+        gamestate = get_mock_pack_opened_gamestate()
+        sm = StrategyManager(strategy)
+        result = sm.render_gamestate(gamestate)
+
+        assert "already spent" in result.lower()
+        assert "does not refund" in result.lower()
+
+    @pytest.mark.parametrize("strategy", ["default", "conservative", "aggressive"])
+    def test_pack_tool_describes_skip_as_no_refund(self, strategy: str) -> None:
+        """Pack tool description must say skipping does not refund the purchase."""
+        sm = StrategyManager(strategy)
+        tools = sm.get_tools("SMODS_BOOSTER_OPENED")
+        pack_tool = next(t for t in tools if t["function"]["name"] == "pack")
+        description = pack_tool["function"]["description"].lower()
+
+        assert "does not refund" in description
+
+
+class TestRenderPackPlayingCardModifiers:
+    """Pack playing cards must render modifier fields from card.modifier."""
+
+    @pytest.mark.parametrize("strategy", ["default", "conservative", "aggressive"])
+    def test_pack_card_renders_enhancement_edition_and_seal(
+        self, strategy: str
+    ) -> None:
+        """Opened Standard pack cards expose enhancement/edition/seal to the LLM."""
+        gamestate = get_mock_pack_opened_gamestate()
+        sm = StrategyManager(strategy)
+        result = sm.render_gamestate(gamestate)
+
+        assert "**GLASS Enhancement**" in result
+        assert "**FOIL Edition**" in result
+        assert "**RED Seal**" in result
+
+    @pytest.mark.parametrize("strategy", ["default", "conservative", "aggressive"])
+    def test_pack_hand_targeting_renders_enhancement(self, strategy: str) -> None:
+        """Hand cards shown during pack targeting include enhancement."""
+        hand_card = get_mock_pack_playing_card(
+            {
+                "id": 2,
+                "key": "H_A",
+                "set": "ENHANCED",
+                "label": "Steel Card",
+                "value": {"rank": "A", "suit": "H", "effect": "X1.5 Mult"},
+                "modifier": {"enhancement": "STEEL"},
+            }
+        )
+        gamestate = get_mock_pack_opened_gamestate(
+            {
+                "hand": {
+                    "count": 1,
+                    "limit": 8,
+                    "cards": [hand_card],
+                    "highlighted_limit": 5,
+                }
+            }
+        )
+        sm = StrategyManager(strategy)
+        result = sm.render_gamestate(gamestate)
+
+        assert "Your Hand (for targeting)" in result
+        assert "(STEEL)" in result
+
+
 class TestRenderMemoryProperties:
     """Property tests for memory template."""