diff --git a/src/glue/CRealmList.cpp b/src/glue/CRealmList.cpp
index 4e8c51c..1952faa 100644
--- a/src/glue/CRealmList.cpp
+++ b/src/glue/CRealmList.cpp
@@ -26,6 +26,93 @@ void CRealmList::Initialize() {
     // TODO Initialize CRealmList::s_sortCriteria
 }
 
+void CRealmList::SetPreferredInfo(uint32_t categoryIndex, int32_t pvp, int32_t rp) {
+    if (CRealmList::s_categories.Count() == 0) {
+        return;
+    }
+
+    auto selectedCategory = CRealmList::Sub4DE910(categoryIndex - 1);
+    if (selectedCategory > CRealmList::s_categories.Count()) {
+        selectedCategory = 0;
+    }
+
+    CRealmList::s_selectedCategory = static_cast<int32_t>(selectedCategory);
+    CRealmList::s_preferredCategory = CRealmList::s_categories[selectedCategory]->m_category->GetID();
+
+    auto realmCategory = CRealmList::s_categories[selectedCategory];
+    int32_t realmId = -1;
+
+    // Attempt to find realm that matches selected category and pvp / rp type
+    for (int32_t i = 0; i < realmCategory->uint14; i++) {
+        auto realmIndex = static_cast<int32_t>(realmCategory->m_realms[i]);
+        auto realmInfo = ClientServices::GetRealmInfoByIndex(realmIndex);
+
+        // 0x1 - INVALID, 0x2 - OFFLINE
+        if (realmInfo->flags & (0x1 | 0x2)) {
+            continue;
+        }
+
+        // 0x20 - FORCE_RECOMMENDED
+        if (realmInfo->flags & 0x20) {
+            realmId = i + 1;
+            break;
+        }
+
+        // Look up realm pvp / rp type based on realm type
+        int32_t realmIsPvp = 0;
+        int32_t realmIsRp = 0;
+        for (int32_t j = 0; j < g_cfg_ConfigsDB.m_numRecords; j++) {
+            auto config = g_cfg_ConfigsDB.GetRecordByIndex(j);
+
+            if (config->m_realmType == realmInfo->type) {
+                realmIsPvp = config->m_playerKillingAllowed != 0;
+                realmIsRp = config->m_roleplaying != 0;
+                break;
+            }
+        }
+
+        if (pvp == realmIsPvp && rp == realmIsRp) {
+            realmId = i + 1;
+
+            // 0x80 - FORCE_FULL
+            if (!(realmInfo->flags & 0x80)) {
+                break;
+            }
+        }
+    }
+
+    // No match found for selected category and pvp / rp type
+    if (realmId == -1) {
+        FrameScript_SignalEvent(9, nullptr);
+        return;
+    }
+
+    FrameScript_SignalEvent(18, "%d%d", categoryIndex, realmId);
+}
+
+uint32_t CRealmList::Sub4DE910(uint32_t a1) {
+    if (CRealmList::s_categories.Count() == 0) {
+        return 0;
+    }
+
+    int32_t v1 = -1;
+
+    uint32_t i;
+    for (i = 0; i < CRealmList::s_categories.Count(); i++) {
+        auto realmCategory = CRealmList::s_categories[i];
+
+        if (realmCategory && realmCategory->uint14 > 0) {
+            v1++;
+
+            if (v1 == a1) {
+                break;
+            }
+        }
+    }
+
+    return i;
+}
+
 void CRealmList::UpdateList() {
     CRealmList::s_avgLoad = 0.0f;
     int32_t category = -1;
diff --git a/src/glue/CRealmList.hpp b/src/glue/CRealmList.hpp
index 35ad34d..bb7e9e1 100644
--- a/src/glue/CRealmList.hpp
+++ b/src/glue/CRealmList.hpp
@@ -22,6 +22,8 @@ class CRealmList {
 
         // Static functions
         static void Initialize();
+        static void SetPreferredInfo(uint32_t index, int32_t pvp, int32_t rp);
+        static uint32_t Sub4DE910(uint32_t a1);
         static void UpdateList();
 };
 
diff --git a/src/ui/ScriptFunctionsRealmList.cpp b/src/ui/ScriptFunctionsRealmList.cpp
index 59bc1ce..52f7b5c 100644
--- a/src/ui/ScriptFunctionsRealmList.cpp
+++ b/src/ui/ScriptFunctionsRealmList.cpp
@@ -1,4 +1,6 @@
 #include "ui/ScriptFunctions.hpp"
+#include "glue/CRealmList.hpp"
+#include "util/StringTo.hpp"
 #include "ui/Types.hpp"
 #include "util/Lua.hpp"
 #include "util/Unimplemented.hpp"
@@ -33,7 +35,17 @@ int32_t Script_GetRealmCategories(lua_State* L) {
 }
 
 int32_t Script_SetPreferredInfo(lua_State* L) {
-    WHOA_UNIMPLEMENTED();
+    if (!lua_isnumber(L, 1)) {
+        return luaL_error(L, "Usage: SetPreferredInfo(index, pvp, rp)");
+    }
+
+    uint32_t index = lua_tonumber(L, 1);
+    int32_t pvp = StringToBOOL(L, 2, 0);
+    int32_t rp = StringToBOOL(L, 3, 0);
+
+    CRealmList::SetPreferredInfo(index, pvp, rp);
+
+    return 0;
 }
 
 int32_t Script_SortRealms(lua_State* L) {