diff --git a/desktop-client/README.md b/desktop-client/README.md
index afb74d9..d83f10e 100644
--- a/desktop-client/README.md
+++ b/desktop-client/README.md
@@ -24,12 +24,13 @@ does not yet have ready-check controls.
 
 ## Fight-night commands
 
-- `/ko` — K.O.: That's a wrap.
+- `/ko` — a large arcade-style K.O. with gold lettering, red outline, and an impact animation.
 - `/bell` — DING!: Back to your corners.
 - `/tap` — TAP!: Someone's had enough.
 - `/robbery` — a reaction plus a 30-second room vote on the decision.
 
-Reactions slide into the bottom of the video for 2.2 seconds and keep playback
+The K.O. appears across the center of the video; other reactions slide into the
+bottom. Effects clear after 2.2 seconds and keep playback
 running. A shared 3-second cooldown limits room-wide effects. Reaction events
 stay in chat history; joining or reconnecting does not replay animations.
 
diff --git a/desktop-client/fight_reactions.py b/desktop-client/fight_reactions.py
index f7120ba..897c882 100644
--- a/desktop-client/fight_reactions.py
+++ b/desktop-client/fight_reactions.py
@@ -4,7 +4,8 @@ from pathlib import Path
 import struct
 import wave
 
-from PyQt6.QtCore import Qt, QTimer, QPropertyAnimation, QPoint, QEasingCurve, QEvent
+from PyQt6.QtCore import Qt, QTimer, QPropertyAnimation, QVariantAnimation, QPoint, QEasingCurve, QEvent
+from PyQt6.QtGui import QPainter, QPainterPath, QFont, QColor, QPen, QLinearGradient, QTransform
 from PyQt6.QtWidgets import QApplication, QWidget, QFrame, QLabel, QHBoxLayout, QVBoxLayout
 
 
@@ -50,6 +51,58 @@ def write_reaction_sound(directory, kind):
     return path
 
 
+class ArcadeKnockout(QWidget):
+    """Vector-painted arcade lettering scales cleanly with the video surface."""
+    def __init__(self, parent):
+        super().__init__(parent)
+        self.progress = 0.0
+        self.setAttribute(Qt.WidgetAttribute.WA_TranslucentBackground)
+
+    def set_progress(self, value):
+        self.progress = value
+        self.update()
+
+    def paintEvent(self, event):
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.RenderHint.Antialiasing)
+        t = self.progress
+        opacity = min(1.0, t / .035, max(0.0, (1.0 - t) / .18))
+        painter.setOpacity(opacity)
+        painter.translate(self.width() / 2, self.height() / 2)
+        entry = min(1.0, t / .18)
+        scale = 1.0 + .65 * (1 - entry) ** 3 - .06 * math.sin(entry * math.pi)
+        painter.scale(scale, scale)
+        font = QFont("Impact")
+        font.setPixelSize(180)
+        font.setBold(True)
+        letters = QPainterPath()
+        letters.addText(0, 0, font, "K.O.")
+        letters = QTransform().shear(-.12, 0).map(letters)
+        bounds = letters.boundingRect()
+        fit = min(self.width() * .63 / bounds.width(), self.height() * .40 / bounds.height())
+        painter.scale(fit, fit)
+        painter.translate(-bounds.center())
+        shadow = QTransform().translate(7, 10).map(letters)
+        painter.setPen(QPen(QColor("#131017"), 18, Qt.PenStyle.SolidLine, Qt.PenCapStyle.RoundCap, Qt.PenJoinStyle.RoundJoin))
+        painter.setBrush(QColor("#131017"))
+        painter.drawPath(shadow)
+        painter.setPen(QPen(QColor("#8b1028"), 14, Qt.PenStyle.SolidLine, Qt.PenCapStyle.RoundCap, Qt.PenJoinStyle.RoundJoin))
+        painter.setBrush(QColor("#f33c35"))
+        painter.drawPath(letters)
+        gradient = QLinearGradient(0, bounds.top(), 0, bounds.bottom())
+        gradient.setColorAt(0, QColor("#fff7b0"))
+        gradient.setColorAt(.40, QColor("#ffe252"))
+        gradient.setColorAt(1, QColor("#ff9c22"))
+        painter.setPen(QPen(QColor("#ff583e"), 5, Qt.PenStyle.SolidLine, Qt.PenCapStyle.RoundCap, Qt.PenJoinStyle.RoundJoin))
+        painter.setBrush(gradient)
+        painter.drawPath(letters)
+        if t < .32:
+            painter.setOpacity(opacity * (1 - t / .32) * .55)
+            painter.setClipPath(letters)
+            sweep = bounds.left() + bounds.width() * min(1.0, t / .32)
+            painter.fillRect(int(sweep), int(bounds.top() - 10), 16, int(bounds.height() + 20), QColor("#fffef0"))
+
+
 class RingsideStrip(QWidget):
     """A separate native window stays above VLC's native video surface."""
     def __init__(self, video_frame):
@@ -65,6 +118,15 @@ class RingsideStrip(QWidget):
         outer.setContentsMargins(0, 0, 0, 0)
         self.panel = QFrame()
         outer.addWidget(self.panel)
+        self.ko_canvas = ArcadeKnockout(self)
+        outer.addWidget(self.ko_canvas)
+        self.ko_canvas.hide()
+        self.kind = None
+        self.ko_animation = QVariantAnimation(self)
+        self.ko_animation.setDuration(2200)
+        self.ko_animation.setStartValue(0.0)
+        self.ko_animation.setEndValue(1.0)
+        self.ko_animation.valueChanged.connect(self.ko_canvas.set_progress)
         row = QHBoxLayout(self.panel)
         row.setContentsMargins(14, 10, 14, 10)
         row.setSpacing(14)
@@ -112,8 +174,18 @@ class RingsideStrip(QWidget):
         self.caption.setText(f"{author}: {caption}")
         self.metadata.setText(f"Room reaction · {position}")
         self.panel.setStyleSheet(f"QFrame {{ background: #1a1b20; border-left: 3px solid {color}; border-radius: 6px; }} QLabel {{ border: none; }}")
+        self.kind = kind
+        self.panel.setVisible(kind != "ko")
+        self.ko_canvas.setVisible(kind == "ko")
+        self.ko_animation.stop()
         self.slide.stop()
         self._place()
+        if kind == "ko":
+            self.ko_canvas.set_progress(0.0)
+            self.show()
+            self.ko_animation.start()
+            self.dismiss_timer.start(2200)
+            return True
         end = self.pos()
         self.move(end + QPoint(0, 12))
         self.show()
@@ -124,6 +196,12 @@ class RingsideStrip(QWidget):
         return True
 
     def _place(self):
+        if self.kind == "ko":
+            self.setFixedSize(self.video_frame.size())
+            self.move(self.video_frame.mapToGlobal(QPoint(0, 0)))
+            return
+        self.setMinimumSize(0, 0)
+        self.setMaximumSize(16777215, 16777215)
         width = max(1, min(540, self.video_frame.width() - 32))
         self.setFixedWidth(width)
         height = self.layout().heightForWidth(width)
@@ -141,6 +219,7 @@ class RingsideStrip(QWidget):
         return super().eventFilter(watched, event)
 
     def dismiss(self):
+        self.ko_animation.stop()
         self.slide.stop()
         self.dismiss_timer.stop()
         self.hide()
diff --git a/desktop-client/test_fight_reactions.py b/desktop-client/test_fight_reactions.py
index 87ad53d..bab914e 100644
--- a/desktop-client/test_fight_reactions.py
+++ b/desktop-client/test_fight_reactions.py
@@ -75,6 +75,24 @@ def test_reactions_work_with_chat_popout_focused(room, qtbot):
     popout.close()
 
 
+def test_arcade_ko_covers_video_then_restores_strip(room, qtbot):
+    room.activateWindow()
+    qtbot.wait(30)
+    room.handle_fight_reaction({'kind': 'ko', 'position': 0})
+    overlay = room.ringside_strip
+    assert overlay.size() == room.video_frame.size()
+    assert overlay.panel.isHidden()
+    assert not overlay.ko_canvas.isHidden()
+    assert overlay.ko_animation.state() == overlay.ko_animation.State.Running
+    room.handle_fight_reaction({'kind': 'bell', 'position': 0})
+    assert overlay.ko_canvas.isHidden()
+    assert not overlay.panel.isHidden()
+    assert overlay.width() <= 540
+    assert overlay.height() < room.video_frame.height()
+    room.cleanup()
+    assert overlay.ko_animation.state() == overlay.ko_animation.State.Stopped
+
+
 def test_sound_is_enabled_by_default_and_background_effects_are_suppressed(room, qtbot, monkeypatch):
     play = Mock()
     monkeypatch.setattr(room, '_play_reaction_sound', play)