diff --git a/doomsday/apps/plugins/common/src/game/g_game.cpp b/doomsday/apps/plugins/common/src/game/g_game.cpp
index 533b718fc3..5fc143427a 100644
--- a/doomsday/apps/plugins/common/src/game/g_game.cpp
+++ b/doomsday/apps/plugins/common/src/game/g_game.cpp
@@ -466,15 +466,7 @@ void R_LoadColorPalettes()
         {
             if (i == numPerClass) break; // Not present.
 
-            String lumpName;
-            if (xlatNum < 10)
-            {
-                lumpName = String("TRANTBL%1").arg(xlatNum);
-            }
-            else
-            {
-                lumpName = String("TRANTBL%1").arg('A' + (xlatNum - 10));
-            }
+            String lumpName = String::format("TRANTBL%X", xlatNum);
             xlatNum++;
 
             LOG_AS("R_LoadColorPalettes")
@@ -3047,8 +3039,7 @@ static void registerGameStatusCVars()
     // Fourth-weapon pieces:
     for (int i = 0; i < WEAPON_FOURTH_PIECE_COUNT; ++i)
     {
-        Block const cvarName = String("player-weapon-piece%1").arg(i + 1).toUtf8();
-        C_VAR_INT(cvarName.constData(), &gsvWPieces[i], READONLYCVAR, 0, 1);
+        C_VAR_INT(String::format("player-weapon-piece%i", i + 1), &gsvWPieces[i], READONLYCVAR, 0, 1);
     }
     C_VAR_INT("player-weapon-allpieces", &gsvWPieces[WEAPON_FOURTH_PIECE_COUNT], READONLYCVAR, 0, 1);
 #endif
diff --git a/doomsday/apps/plugins/common/src/game/gamesession.cpp b/doomsday/apps/plugins/common/src/game/gamesession.cpp
index 06d89865d9..09f9c308bd 100644
--- a/doomsday/apps/plugins/common/src/game/gamesession.cpp
+++ b/doomsday/apps/plugins/common/src/game/gamesession.cpp
@@ -103,7 +103,7 @@ namespace internal
 
 using namespace internal;
 
-static String const internalSavePath = "/home/cache/internal.save";
+DE_STATIC_STRING(internalSavePath, "/home/cache/internal.save");
 static GameSession theSession;
 
 DE_PIMPL(GameSession)
@@ -130,13 +130,13 @@ DE_PIMPL(GameSession)
     void cleanupInternalSave()
     {
         // Ensure the internal save folder exists.
-        App::fileSystem().makeFolder(internalSavePath.fileNamePath());
+        App::fileSystem().makeFolder(internalSavePath().fileNamePath());
 
         // Ensure that any pre-existing internal save is destroyed.
         // This may happen if the game was not shutdown properly in the event of a crash.
         /// @todo It may be possible to recover this session if it was written successfully
         /// before the fatal error occurred.
-        AbstractSession::removeSaved(internalSavePath);
+        AbstractSession::removeSaved(internalSavePath());
     }
 
     void resetStateForNewSession()
@@ -532,19 +532,19 @@ DE_PIMPL(GameSession)
 
         self().setInProgress(false);
 
-        if (savePath.compareWithoutCase(internalSavePath))
+        if (savePath.compareWithoutCase(internalSavePath()))
         {
             // Perform necessary prep.
             cleanupInternalSave();
 
             // Copy the save to the internal savegame.
-            AbstractSession::copySaved(internalSavePath, savePath);
+            AbstractSession::copySaved(internalSavePath(), savePath);
         }
 
         //
         // GameStateFolder deserialization begins.
         //
-        auto const &saved = App::rootFolder().locate<GameStateFolder>(internalSavePath);
+        auto const &saved = App::rootFolder().locate<GameStateFolder>(internalSavePath());
         GameStateMetadata const &metadata = saved.metadata();
 
         // Ensure a complete game ruleset is available.
@@ -693,7 +693,7 @@ DE_PIMPL(GameSession)
 #endif
 
             String const mapUriAsText = self().mapUri().compose();
-            auto const &saved = App::rootFolder().locate<GameStateFolder>(internalSavePath);
+            auto const &saved = App::rootFolder().locate<GameStateFolder>(internalSavePath());
             std::unique_ptr<GameStateFolder::MapStateReader> reader(makeMapStateReader(saved, mapUriAsText));
             self().setThinkerMapping(reader.get());
             reader->read(mapUriAsText);
@@ -1054,7 +1054,7 @@ void GameSession::end()
         G_ResetViewEffects();
     }
 
-    AbstractSession::removeSaved(internalSavePath);
+    AbstractSession::removeSaved(internalSavePath());
 
     setInProgress(false);
     LOG_MSG("Game ended");
@@ -1123,7 +1123,7 @@ void GameSession::begin(GameRules const &newRules, String const &episodeId,
     d->reloadMap();
 
     // Create the internal .save session package.
-    d->updateGameStateFolder(internalSavePath, metadata);
+    d->updateGameStateFolder(internalSavePath(), metadata);
 }
 
 void GameSession::reloadMap()
@@ -1138,7 +1138,7 @@ void GameSession::reloadMap()
     {
         try
         {
-            d->loadSaved(internalSavePath);
+            d->loadSaved(internalSavePath());
             return;
         }
         catch (Error const &er)
@@ -1164,7 +1164,7 @@ void GameSession::reloadMap()
         d->reloadMap();
 
         // Create the internal .save session package.
-        d->updateGameStateFolder(internalSavePath, d->metadata());
+        d->updateGameStateFolder(internalSavePath(), d->metadata());
 
         ::briefDisabled = oldBriefDisabled;
     }
@@ -1202,7 +1202,7 @@ void GameSession::leaveMap(res::Uri const &nextMapUri, uint nextMapEntryPoint)
     GameStateFolder *saved = nullptr;
     if (!d->rules.values.deathmatch) // Never save in deathmatch.
     {
-        saved = &App::rootFolder().locate<GameStateFolder>(internalSavePath);
+        saved = &App::rootFolder().locate<GameStateFolder>(internalSavePath());
         auto &mapsFolder = saved->locate<Folder>("maps");
 
         DE_ASSERT(saved->mode().testFlag(File::Write));
@@ -1323,7 +1323,7 @@ void GameSession::leaveMap(res::Uri const &nextMapUri, uint nextMapEntryPoint)
 String GameSession::userDescription()
 {
     if (!hasBegun()) return "";
-    return App::rootFolder().locate<GameStateFolder>(internalSavePath)
+    return App::rootFolder().locate<GameStateFolder>(internalSavePath())
                                 .metadata().gets("userDescription", "");
 }
 
@@ -1356,13 +1356,13 @@ void GameSession::save(String const &saveName, String const &userDescription)
         metadata.set("userDescription", chooseSaveDescription(savePath, userDescription));
 
         // Update the existing internal .save package.
-        d->updateGameStateFolder(internalSavePath, metadata);
+        d->updateGameStateFolder(internalSavePath(), metadata);
 
         // In networked games the server tells the clients to save also.
         NetSv_SaveGame(metadata.getui("sessionId"));
 
         // Copy the internal saved session to the destination slot.
-        AbstractSession::copySaved(savePath, internalSavePath);
+        AbstractSession::copySaved(savePath, internalSavePath());
 
         P_SetMessage(&players[CONSOLEPLAYER], TXT_GAMESAVED);
 
diff --git a/doomsday/apps/plugins/common/src/game/saveslots.cpp b/doomsday/apps/plugins/common/src/game/saveslots.cpp
index d4d4f71fa6..7558f2cc8c 100644
--- a/doomsday/apps/plugins/common/src/game/saveslots.cpp
+++ b/doomsday/apps/plugins/common/src/game/saveslots.cpp
@@ -201,7 +201,7 @@ void SaveSlots::Slot::setGameStateFolder(GameStateFolder *newSession)
         String statusText;
         if (d->session)
         {
-            statusText = String("associated with \"%1\"").arg(d->session->path());
+            statusText = String::format("associated with \"%s\"", d->session->path().c_str());
         }
         else
         {
@@ -299,7 +299,7 @@ DE_PIMPL(SaveSlots)
     void setAllIndexedSaves()
     {
         auto const &index = SaveGames::get().saveIndex();
-        foreach (File *file, index.files())
+        for (File *file : index.files())
         {
             fileAdded(*file, index);
         }
diff --git a/doomsday/apps/plugins/common/src/hu_menu.cpp b/doomsday/apps/plugins/common/src/hu_menu.cpp
index e361fa55c1..ecb9acab37 100644
--- a/doomsday/apps/plugins/common/src/hu_menu.cpp
+++ b/doomsday/apps/plugins/common/src/hu_menu.cpp
@@ -2188,7 +2188,7 @@ void Hu_MenuInitPlayerClassPage()
         btn->setFixedY(y);
         btn->setAction(Widget::Deactivated, Hu_MenuSelectPlayerClass);
         btn->setAction(Widget::FocusGained, Hu_MenuFocusOnPlayerClass);
-        btn->setUserValue2(int(info->plrClass));
+        btn->setUserValue2(NumberValue(info->plrClass));
         btn->setFont(MENU_FONT1);
 
         page->addWidget(btn);
@@ -2197,11 +2197,11 @@ void Hu_MenuInitPlayerClassPage()
 
     // Random class button.
     String const labelText = GET_TXT(TXT_RANDOMPLAYERCLASS);
-    int const shortcut     = iswlanum(labelText.first())? labelText.first() : 0;
+    int const shortcut     = iswalnum(labelText.first())? labelText.first() : 0;
     page->addWidget(new ButtonWidget(labelText))
             .setFixedY(y)
             .setShortcut(shortcut)
-            .setUserValue2(int(PCLASS_NONE))
+            .setUserValue2(NumberValue(PCLASS_NONE))
             .setFont(MENU_FONT1)
             .setColor(MENU_COLOR1)
             .setAction(Widget::Deactivated, Hu_MenuSelectPlayerClass)
@@ -2957,7 +2957,7 @@ void Hu_MenuPlayerClassBackgroundTicker(Widget &wi)
     ///        state through a focus action.
     if(Widget *mop = wi.page().focusWidget())
     {
-        playerclass_t pClass = playerclass_t(mop->userValue2().toInt());
+        playerclass_t pClass = playerclass_t(mop->userValue2().asInt());
         if(pClass == PCLASS_NONE)
         {
             // Random class.
@@ -2985,7 +2985,7 @@ void Hu_MenuPlayerClassPreviewTicker(Widget &wi)
     ///        state through a focus action.
     if(Widget *mop = wi.page().focusWidget())
     {
-        playerclass_t pClass = playerclass_t(mop->userValue2().toInt());
+        playerclass_t pClass = playerclass_t(mop->userValue2().asInt());
         if(pClass == PCLASS_NONE)
         {
             // Random class.
@@ -3495,7 +3495,7 @@ void Hu_MenuSelectSaveGame(Widget & /*wi*/, Widget::Action action)
 void Hu_MenuSelectPlayerClass(Widget &wi, Widget::Action action)
 {
     Page &skillPage = Hu_MenuPage("Skill");
-    int option = wi.userValue2().toInt();
+    int option = wi.userValue2().asInt();
 
     if(action != Widget::Deactivated) return;
 
diff --git a/doomsday/apps/plugins/common/src/hud/widgets/chainwidget.cpp b/doomsday/apps/plugins/common/src/hud/widgets/chainwidget.cpp
index 35d3a3de55..d9ab74fddc 100644
--- a/doomsday/apps/plugins/common/src/hud/widgets/chainwidget.cpp
+++ b/doomsday/apps/plugins/common/src/hud/widgets/chainwidget.cpp
@@ -409,21 +409,21 @@ void guidata_chain_t::prepareAssets()
     ::pGem[PCLASS_FIGHTER][0] = R_DeclarePatch("LIFEGEM");
     for(dint i = 1; i < NUMTEAMS; ++i)
     {
-        ::pGem[PCLASS_FIGHTER][i] = R_DeclarePatch(String("LIFEGMF%1").arg(i + 1));
+        ::pGem[PCLASS_FIGHTER][i] = R_DeclarePatch(String::format("LIFEGMF%i", i + 1));
     }
 
     // Cleric:
     ::pChain[PCLASS_CLERIC] = R_DeclarePatch("CHAIN2");
     for(dint i = 0; i < NUMTEAMS; ++i)
     {
-        ::pGem[PCLASS_CLERIC][i] = R_DeclarePatch(String("LIFEGMC%1").arg(i + 1));
+        ::pGem[PCLASS_CLERIC][i] = R_DeclarePatch(String::format("LIFEGMC%i", i + 1));
     }
 
     // Mage:
     ::pChain[PCLASS_MAGE] = R_DeclarePatch("CHAIN3");
     for(dint i = 0; i < NUMTEAMS; ++i)
     {
-        ::pGem[PCLASS_MAGE][i] = R_DeclarePatch(String("LIFEGMM%1").arg(i + 1));
+        ::pGem[PCLASS_MAGE][i] = R_DeclarePatch(String::format("LIFEGMM%i", i + 1));
     }
 #endif
 }
diff --git a/doomsday/apps/plugins/common/src/hud/widgets/flightwidget.cpp b/doomsday/apps/plugins/common/src/hud/widgets/flightwidget.cpp
index e772247b98..395f08262f 100644
--- a/doomsday/apps/plugins/common/src/hud/widgets/flightwidget.cpp
+++ b/doomsday/apps/plugins/common/src/hud/widgets/flightwidget.cpp
@@ -150,7 +150,7 @@ void guidata_flight_t::prepareAssets()  // static
 #if __JHERETIC__ || __JHEXEN__
     for(dint i = 0; i < 16; ++i)
     {
-        ::pIcon[i] = R_DeclarePatch(String("SPFLY%1").arg(i));
+        ::pIcon[i] = R_DeclarePatch(String::format("SPFLY%i", i));
     }
 #endif
 }
diff --git a/doomsday/apps/plugins/common/src/hud/widgets/itemswidget.cpp b/doomsday/apps/plugins/common/src/hud/widgets/itemswidget.cpp
index e2a661b099..c3c6b002a2 100644
--- a/doomsday/apps/plugins/common/src/hud/widgets/itemswidget.cpp
+++ b/doomsday/apps/plugins/common/src/hud/widgets/itemswidget.cpp
@@ -120,14 +120,14 @@ void guidata_items_t::updateGeometry()
     String valueAsText("Items:");
     if(cfg.common.hudShownCheatCounters & CCH_ITEMS)
     {
-        valueAsText += String(" %1/%2").arg(_value).arg(totalItems);
+        valueAsText += String::format(" %i/%i", _value, totalItems);
     }
     if(cfg.common.hudShownCheatCounters & CCH_ITEMS_PRCNT)
     {
-        valueAsText += String(" %1%2%%3")
-                           .arg((::cfg.common.hudShownCheatCounters & CCH_ITEMS) ? "(" : "")
-                           .arg(totalItems ? _value * 100 / totalItems : 100)
-                           .arg((::cfg.common.hudShownCheatCounters & CCH_ITEMS) ? ")" : "");
+        valueAsText += String::format(" %s%i%%%s",
+                                      (::cfg.common.hudShownCheatCounters & CCH_ITEMS) ? "(" : "",
+                                      totalItems ? _value * 100 / totalItems : 100,
+                                      (::cfg.common.hudShownCheatCounters & CCH_ITEMS) ? ")" : "");
     }
 
     FR_SetFont(font());
diff --git a/doomsday/apps/plugins/common/src/hud/widgets/keyswidget.cpp b/doomsday/apps/plugins/common/src/hud/widgets/keyswidget.cpp
index cf2ffda144..0e18c12905 100644
--- a/doomsday/apps/plugins/common/src/hud/widgets/keyswidget.cpp
+++ b/doomsday/apps/plugins/common/src/hud/widgets/keyswidget.cpp
@@ -361,7 +361,7 @@ void guidata_keys_t::prepareAssets()  // static
 #elif __JHEXEN__
     for(dint i = 0; i < NUM_KEY_TYPES; ++i)
     {
-        pKeys[i] = R_DeclarePatch(String("KEYSLOT%1").arg(i + 1, 0, 16).toUpper());
+        pKeys[i] = R_DeclarePatch(String::format("KEYSLOT%X", i + 1));
     }
 #endif
 }
diff --git a/doomsday/apps/plugins/common/src/network/d_netsv.cpp b/doomsday/apps/plugins/common/src/network/d_netsv.cpp
index be13d64ed5..e56a3aefc9 100644
--- a/doomsday/apps/plugins/common/src/network/d_netsv.cpp
+++ b/doomsday/apps/plugins/common/src/network/d_netsv.cpp
@@ -340,7 +340,7 @@ static res::Uri NetSv_ScanCycle(int index, maprule_t *rules = 0)
                     {
                         int tens = tmp[0] == '*' ? RNG_RandByte() % 10 : tmp[0] - '0';
                         int ones = tmp[1] == '*' ? RNG_RandByte() % 10 : tmp[1] - '0';
-                        map = de::String("%1%2").arg(tens).arg(ones).toInt();
+                        map = 10 * tens + ones;
                     }
 #elif __JHERETIC__
                     episode = tmp[0] == '*' ? RNG_RandByte() % 9 : tmp[0] - '0';
@@ -349,7 +349,7 @@ static res::Uri NetSv_ScanCycle(int index, maprule_t *rules = 0)
 #else // __JHEXEN__ || __JDOOM64__
                     int tens = tmp[0] == '*' ? RNG_RandByte() % 10 : tmp[0] - '0';
                     int ones = tmp[1] == '*' ? RNG_RandByte() % 10 : tmp[1] - '0';
-                    map = de::String("%1%2").arg(tens).arg(ones).toInt();
+                    map = 10 * tens + ones;
 #endif
 
 #if __JHEXEN__
@@ -661,9 +661,9 @@ void NetSv_SendGameState(int flags, int to)
 {
     if(!IS_NETWORK_SERVER) return;
 
-    AutoStr *gameId    = AutoStr_FromTextStd(gfw_GameId().toLatin1().constData());
-    AutoStr *episodeId = AutoStr_FromTextStd(gfw_Session()->episodeId().toLatin1().constData());
-    res::Uri mapUri     = gfw_Session()->mapUri();
+    AutoStr *gameId    = AutoStr_FromTextStd(gfw_GameId());
+    AutoStr *episodeId = AutoStr_FromTextStd(gfw_Session()->episodeId());
+    res::Uri mapUri    = gfw_Session()->mapUri();
 
     // Print a short message that describes the game state.
     LOG_NET_NOTE("Sending game setup: %s %s %s %s")
diff --git a/doomsday/apps/plugins/common/src/world/player.cpp b/doomsday/apps/plugins/common/src/world/player.cpp
index 62cdf82d03..8625f330ff 100644
--- a/doomsday/apps/plugins/common/src/world/player.cpp
+++ b/doomsday/apps/plugins/common/src/world/player.cpp
@@ -1807,7 +1807,7 @@ String Player_WeaponId(player_t const *plr)
     }
     else
     {
-        value.append(QString::number(plr->readyWeapon));
+        value.append(String::asText(plr->readyWeapon));
     }
 #endif
 #if defined(__JDOOM__) || defined(__JDOOM64__) || defined(__JHEXEN__)
@@ -1974,7 +1974,7 @@ void Player_UpdateStatusCVars(player_t const *player)
 #if __JHEXEN__
     for(int i = 0; i < WEAPON_FOURTH_PIECE_COUNT; ++i)
     {
-        Path const varPath { String("player-weapon-piece%1").arg(i + 1), CVAR_DELIM };
+        const Path varPath{String::format("player-weapon-piece%i", i + 1), CVAR_DELIM};
         Con_SetVariable(varPath, (player->pieces & (1 << i))? 1 : 0, SVF_WRITE_OVERRIDE);
     }
     static Path const var_player_weapon_allpieces("player-weapon-allpieces", CVAR_DELIM);