diff --git a/main.lua b/main.lua
index 8197624..0fd53a9 100644
--- a/main.lua
+++ b/main.lua
@@ -309,6 +309,32 @@ function JCA.is_perished(card)
     return not not (a and a.perishable and (a.perish_tally or 0) <= 0)
 end
 
+-- Boss-blind cautions: five bosses debuff a whole class of cards for the
+-- fight (game.lua P_BLINDS; applied in Blind:debuff_card, blind.lua:708):
+-- The Club/Goad/Head/Window each kill a suit, The Plant kills face cards.
+-- A debuffed card scores nothing and triggers nothing, so a joker that wants
+-- that class is walking into a dead ante -- and a joker that GIVES it is
+-- worse (Pareidolia under The Plant makes every card a debuffed face).
+-- Warning-only, like every trap: this never touches a score.
+local BOSS_KILLS = {
+    bl_club   = {tag = 'clubs',    what = 'Clubs'},
+    bl_goad   = {tag = 'spades',   what = 'Spades'},
+    bl_head   = {tag = 'hearts',   what = 'Hearts'},
+    bl_window = {tag = 'diamonds', what = 'Diamonds'},
+    bl_plant  = {tag = 'faces',    what = 'face cards'},
+}
+JCA.boss_kills = BOSS_KILLS
+
+-- The boss still ahead this ante, or nil once it is dealt with. Both fields
+-- live in G.GAME.round_resets (game.lua:2019, misc_functions.lua:398).
+function JCA.upcoming_boss()
+    local rr = G.GAME and G.GAME.round_resets
+    if not (rr and rr.blind_choices) then return nil end
+    local state = rr.blind_states and rr.blind_states.Boss
+    if state == 'Defeated' or state == 'Skipped' then return nil end
+    return rr.blind_choices.Boss
+end
+
 function JCA.weakest_link()
     if not (G.jokers and G.jokers.cards) then return nil end
     local cards = G.jokers.cards
@@ -592,6 +618,19 @@ local function tooltip_rows(card)
     local caution = in_buy_area(card) and JCA.cautions[key]
     if caution then text_row('Caution: ' .. caution, G.C.RED) end
 
+    -- Boss caution: buying a joker whose card class the upcoming boss
+    -- debuffs is paying for a dead ante. Warnings survive learning mode.
+    if in_buy_area(card) then
+        local boss = JCA.upcoming_boss()
+        local kill = boss and BOSS_KILLS[boss]
+        local entry = JCA.db[key]
+        if kill and entry and (entry.wants[kill.tag] or entry.gives[kill.tag]) then
+            local bname = G.P_BLINDS and G.P_BLINDS[boss] and G.P_BLINDS[boss].name
+            text_row(('This ante: %s debuffs %s'):format(bname or 'the boss', kill.what),
+                G.C.RED)
+        end
+    end
+
     -- Sticker facts (any area -- higher stakes put stickers on shop jokers
     -- too). Mechanical numbers from the game source, not judgements, so
     -- learning mode keeps them.
diff --git a/test.lua b/test.lua
index 067c9e0..68f844f 100644
--- a/test.lua
+++ b/test.lua
@@ -415,6 +415,35 @@ per[2].ability = {perishable = true, perish_tally = 0}
 eq(JCA.weakest_link(), per[2],
     'but a perished joker is the cut at any score - it will never work again')
 
+--------------------------------------------------------------------------------
+section('Engine: boss-blind cautions know who the boss silences')
+--------------------------------------------------------------------------------
+
+-- The five class-killer bosses, verbatim from game.lua's P_BLINDS debuff
+-- configs. Every tag they reference must exist in the database, or the
+-- caution can never fire.
+for boss, kill in pairs(JCA.boss_kills) do
+    ok(JCA.tag_label[kill.tag], ('boss %s kills a real catalog tag (%s)'):format(boss, kill.tag))
+end
+
+-- The Plant debuffs faces: it must catch both the payoff (Business Card
+-- wants faces) and the enabler (Pareidolia turns every card into one).
+local plant = JCA.boss_kills.bl_plant
+ok(JCA.db.j_business.wants[plant.tag], 'The Plant caution catches face payoffs')
+ok(JCA.db.j_pareidolia.gives[plant.tag], 'and face enablers, whose conversion kills the deck')
+
+-- Upcoming-boss reading: warn while the boss is ahead, stay quiet once it
+-- is dealt with.
+G.GAME.round_resets = {
+    blind_choices = {Small = 'bl_small', Big = 'bl_big', Boss = 'bl_plant'},
+    blind_states = {Small = 'Defeated', Big = 'Current', Boss = 'Upcoming'},
+}
+eq(JCA.upcoming_boss(), 'bl_plant', 'the upcoming boss is read from round_resets')
+G.GAME.round_resets.blind_states.Boss = 'Defeated'
+eq(JCA.upcoming_boss(), nil, 'a defeated boss warns nobody')
+G.GAME.round_resets = nil
+eq(JCA.upcoming_boss(), nil, 'no round state (menus, tests) reads as no boss')
+
 --------------------------------------------------------------------------------
 section('Engine: Ceremonial Dagger names its victim')
 --------------------------------------------------------------------------------