From c30eea477da4d065c172040125b3125d2f5fd985 Mon Sep 17 00:00:00 2001
From: PatR <rankin@nethack.org>
Date: Thu, 12 Mar 2026 13:12:42 -0700
Subject: [PATCH] Shroedinger's dead cat

Give experience to the hero if opening Shroedinger's Box reveals a cat
corpse rather than releasing a live cat.

It feels a bit odd to assess a bonus rather than a penalty.
---
 doc/fixes3-7-0.txt |  1 +
 src/pickup.c       | 15 +++++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index c9803c5a2..54dcaa9fb 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1581,6 +1581,7 @@ the "bustling town" minetown has more peacefuls
 healers may get tiny damage increase when attacking with knives
 allow rogues to also backstab sleeping or paralyzed monsters
 rogues cannot backstab monsters that have no backside
+give experience if opening Schroedinger's Box causes death of the cat inside
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository
diff --git a/src/pickup.c b/src/pickup.c
index bd1fe41db..73c513135 100644
--- a/src/pickup.c
+++ b/src/pickup.c
@@ -1,4 +1,4 @@
-/* NetHack 3.7	pickup.c	$NHDT-Date: 1720074481 2024/07/04 06:28:01 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.374 $ */
+/* NetHack 3.7	pickup.c	$NHDT-Date: 1773373633 2026/03/12 19:47:13 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.386 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2012. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -2860,6 +2860,9 @@ observe_quantum_cat(struct obj *box, boolean makecat, boolean givemsg)
         }
     } else {
         box->spe = 0; /* now an ordinary box (with a cat corpse inside) */
+        if (givemsg)
+            pline_The("%s inside the box is dead!",
+                      Hallucination ? rndmonnam((char *) 0) : "housecat");
         if (deadcat) {
             /* set_corpsenm() will start the rot timer that was removed
                when makemon() created SchroedingersBox; start it from
@@ -2867,10 +2870,14 @@ observe_quantum_cat(struct obj *box, boolean makecat, boolean givemsg)
             deadcat->age = svm.moves;
             set_corpsenm(deadcat, PM_HOUSECAT);
             deadcat = oname(deadcat, sc, ONAME_NO_FLAGS);
+
+            if (!svc.context.mon_moving) {
+                /* give experience points for the death of the cat since
+                   that has been finalized by the hero opening the box */
+                more_experienced(20, 10); /* 20:current exp; 10:score bonus */
+                newexplevel();
+            }
         }
-        if (givemsg)
-            pline_The("%s inside the box is dead!",
-                      Hallucination ? rndmonnam((char *) 0) : "housecat");
     }
     nhUse(deadcat);
     return;