From bab2ce47595ea6a36d3f16637ff52ebb5762ca4e Mon Sep 17 00:00:00 2001
From: WinterSolstice8 <60417494+wintersolstice8@users.noreply.github.com>
Date: Thu, 5 Feb 2026 08:29:35 -0700
Subject: [PATCH] [core] Adjust desynth HQ2/3 algo, add comments

---
 src/map/utils/synthutils.cpp | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/map/utils/synthutils.cpp b/src/map/utils/synthutils.cpp
index 02ac76e34e4..9527224f439 100644
--- a/src/map/utils/synthutils.cpp
+++ b/src/map/utils/synthutils.cpp
@@ -666,16 +666,20 @@ auto calculateDesynthResult(CCharEntity* PChar) -> uint8
 
     // Calculate HQ2 and HQ3 upgrades.
     uint8 upgradeHQ = 0;
-    for (uint8 tries = 0; tries < 2; ++tries)
+
+    // https://www.bluegartr.com/threads/135055-Extensive-Desynthesis-Rate-Research?p=7789195&viewfull=1#post7789195
+    // https://wiki.ffo.jp/html/401.html
+    // In order to achieve a desynth HQ rate distribution of
+    // (NQ , HQ1, HQ2, HQ3)
+    // (40%, 30%, 20%, 10%)
+    // roll a 50% HQ2 rate, then a 33.33(...)% rate for HQ3
+    if (xirand::GetRandomNumber(0.0f, 100.f) < 50.0f)
     {
-        if (xirand::GetRandomNumber(0.0f, 100.f) < 50.0f)
-        {
-            upgradeHQ = 1;
+        upgradeHQ = 1;
 
-            if (xirand::GetRandomNumber(0.0f, 100.f) < 33.0f)
-            {
-                upgradeHQ = 2;
-            }
+        if (xirand::GetRandomNumber(0.0f, 100.f) < 100.f / 3.0f)
+        {
+            upgradeHQ = 2;
         }
     }