diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index 62169b1532..b8a092de35 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -565,8 +565,7 @@ void ShowCostOrIncomeAnimation(int x, int y, int z, Money cost)
 		cost = -cost;
 		msg = STR_INCOME_FLOAT_INCOME;
 	}
-	SetDParam(0, cost);
-	AddTextEffect(msg, pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
+	AddTextEffect(GetEncodedString(msg, cost), pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
 }
 
 /**
@@ -581,17 +580,15 @@ void ShowFeederIncomeAnimation(int x, int y, int z, Money transfer, Money income
 {
 	Point pt = RemapCoords(x, y, z);
 
-	SetDParam(0, transfer);
 	if (income == 0) {
-		AddTextEffect(STR_FEEDER, pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
+		AddTextEffect(GetEncodedString(STR_FEEDER, transfer), pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
 	} else {
 		StringID msg = STR_FEEDER_COST;
 		if (income < 0) {
 			income = -income;
 			msg = STR_FEEDER_INCOME;
 		}
-		SetDParam(1, income);
-		AddTextEffect(msg, pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
+		AddTextEffect(GetEncodedString(msg, transfer, income), pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
 	}
 }
 
@@ -610,8 +607,7 @@ TextEffectID ShowFillingPercent(int x, int y, int z, uint8_t percent, StringID s
 
 	assert(string != STR_NULL);
 
-	SetDParam(0, percent);
-	return AddTextEffect(string, pt.x, pt.y, 0, TE_STATIC);
+	return AddTextEffect(GetEncodedString(string, percent), pt.x, pt.y, 0, TE_STATIC);
 }
 
 /**
@@ -623,8 +619,7 @@ void UpdateFillingPercent(TextEffectID te_id, uint8_t percent, StringID string)
 {
 	assert(string != STR_NULL);
 
-	SetDParam(0, percent);
-	UpdateTextEffect(te_id, string);
+	UpdateTextEffect(te_id, GetEncodedString(string, percent));
 }
 
 /**
diff --git a/src/texteff.cpp b/src/texteff.cpp
index c9a03d9b04..012ee24b8f 100644
--- a/src/texteff.cpp
+++ b/src/texteff.cpp
@@ -21,28 +21,29 @@
 
 /** Container for all information about a text effect */
 struct TextEffect : public ViewportSign {
-	std::vector<StringParameterData> params; ///< Backup of string parameters
-	StringID string_id;  ///< String to draw for the text effect, if INVALID_STRING_ID then it's not valid
-	uint8_t duration;      ///< How long the text effect should stay, in ticks (applies only when mode == TE_RISING)
-	TextEffectMode mode; ///< Type of text effect
+	TextEffectMode mode; ///< Type of text effect.
+	uint8_t duration; ///< How long the text effect should stay, in ticks (applies only when mode == TE_RISING)
+	EncodedString msg; ///< Encoded message for text effect.
 
 	/** Reset the text effect */
 	void Reset()
 	{
 		this->MarkDirty();
 		this->width_normal = 0;
-		this->string_id = INVALID_STRING_ID;
+		this->mode = TE_INVALID;
 	}
+
+	inline bool IsValid() const { return this->mode != TE_INVALID; }
 };
 
-static std::vector<struct TextEffect> _text_effects; ///< Text effects are stored there
+static std::vector<TextEffect> _text_effects; ///< Text effects are stored there
 
 /* Text Effects */
-TextEffectID AddTextEffect(StringID msg, int center, int y, uint8_t duration, TextEffectMode mode)
+TextEffectID AddTextEffect(EncodedString &&msg, int center, int y, uint8_t duration, TextEffectMode mode)
 {
 	if (_game_mode == GM_MENU) return INVALID_TE_ID;
 
-	auto it = std::ranges::find(_text_effects, INVALID_STRING_ID, &TextEffect::string_id);
+	auto it = std::ranges::find_if(_text_effects, [](const TextEffect &te) { return !te.IsValid(); });
 	if (it == std::end(_text_effects)) {
 		/* _text_effects.size() is the maximum ID + 1 that has been allocated. We should not allocate INVALID_TE_ID or beyond. */
 		if (_text_effects.size() >= INVALID_TE_ID) return INVALID_TE_ID;
@@ -52,35 +53,33 @@ TextEffectID AddTextEffect(StringID msg, int center, int y, uint8_t duration, Te
 	TextEffect &te = *it;
 
 	/* Start defining this object */
-	te.string_id = msg;
+	te.msg = std::move(msg);
 	te.duration = duration;
-	CopyOutDParam(te.params, 2);
 	te.mode = mode;
 
 	/* Make sure we only dirty the new area */
 	te.width_normal = 0;
-	te.UpdatePosition(center, y, GetString(te.string_id));
+	te.UpdatePosition(center, y, te.msg.GetDecodedString());
 
 	return static_cast<TextEffectID>(it - std::begin(_text_effects));
 }
 
-void UpdateTextEffect(TextEffectID te_id, StringID msg)
+void UpdateTextEffect(TextEffectID te_id, EncodedString &&msg)
 {
 	/* Update details */
 	TextEffect &te = _text_effects[te_id];
-	if (msg == te.string_id && !HaveDParamChanged(te.params)) return;
-	te.string_id = msg;
-	CopyOutDParam(te.params, 2);
+	if (msg == te.msg) return;
+	te.msg = std::move(msg);
 
-	te.UpdatePosition(te.center, te.top, GetString(te.string_id));
+	te.UpdatePosition(te.center, te.top, te.msg.GetDecodedString());
 }
 
 void UpdateAllTextEffectVirtCoords()
 {
 	for (auto &te : _text_effects) {
-		if (te.string_id == INVALID_STRING_ID) continue;
-		CopyInDParam(te.params);
-		te.UpdatePosition(te.center, te.top, GetString(te.string_id));
+		if (!te.IsValid()) continue;
+
+		te.UpdatePosition(te.center, te.top, te.msg.GetDecodedString());
 	}
 }
 
@@ -94,7 +93,7 @@ IntervalTimer<TimerWindow> move_all_text_effects_interval = {std::chrono::millis
 	if (_pause_mode && _game_mode != GM_EDITOR && _settings_game.construction.command_pause_level <= CMDPL_NO_CONSTRUCTION) return;
 
 	for (TextEffect &te : _text_effects) {
-		if (te.string_id == INVALID_STRING_ID) continue;
+		if (!te.IsValid()) continue;
 		if (te.mode != TE_RISING) continue;
 
 		if (te.duration < count) {
@@ -125,14 +124,13 @@ void DrawTextEffects(DrawPixelInfo *dpi)
 	if (dpi->zoom >= ZOOM_LVL_TEXT_EFFECT) flags.Set(ViewportStringFlag::Small);
 
 	for (const TextEffect &te : _text_effects) {
-		if (te.string_id == INVALID_STRING_ID) continue;
+		if (!te.IsValid()) continue;
 
 		if (te.mode == TE_RISING || _settings_client.gui.loading_indicators) {
 			std::string *str = ViewportAddString(dpi, &te, flags, INVALID_COLOUR);
 			if (str == nullptr) continue;
 
-			CopyInDParam(te.params);
-			*str = GetString(te.string_id);
+			*str = te.msg.GetDecodedString();
 		}
 	}
 }
diff --git a/src/texteff.hpp b/src/texteff.hpp
index dad9b5888d..6dc656117c 100644
--- a/src/texteff.hpp
+++ b/src/texteff.hpp
@@ -18,6 +18,7 @@
  * Text effect modes.
  */
 enum TextEffectMode : uint8_t {
+	TE_INVALID, ///< Text effect is invalid.
 	TE_RISING, ///< Make the text effect slowly go upwards
 	TE_STATIC, ///< Keep the text effect static
 };
@@ -26,10 +27,10 @@ using TextEffectID = uint16_t;
 
 static const TextEffectID INVALID_TE_ID = UINT16_MAX;
 
-TextEffectID AddTextEffect(StringID msg, int x, int y, uint8_t duration, TextEffectMode mode);
+TextEffectID AddTextEffect(EncodedString &&msg, int x, int y, uint8_t duration, TextEffectMode mode);
 void InitTextEffects();
 void DrawTextEffects(DrawPixelInfo *dpi);
-void UpdateTextEffect(TextEffectID effect_id, StringID msg);
+void UpdateTextEffect(TextEffectID effect_id, EncodedString &&msg);
 void RemoveTextEffect(TextEffectID effect_id);
 void UpdateAllTextEffectVirtCoords();
 
diff --git a/src/vehicle_gui.cpp b/src/vehicle_gui.cpp
index b227a32ac0..3756803f5a 100644
--- a/src/vehicle_gui.cpp
+++ b/src/vehicle_gui.cpp
@@ -2981,7 +2981,7 @@ void CcStartStopVehicle(Commands, const CommandCost &result, VehicleID veh_id, b
 
 	StringID msg = (v->vehstatus & VS_STOPPED) ? STR_VEHICLE_COMMAND_STOPPED : STR_VEHICLE_COMMAND_STARTED;
 	Point pt = RemapCoords(v->x_pos, v->y_pos, v->z_pos);
-	AddTextEffect(msg, pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
+	AddTextEffect(GetEncodedString(msg), pt.x, pt.y, Ticks::DAY_TICKS, TE_RISING);
 }
 
 /**