diff --git a/proto/apl.proto b/proto/apl.proto
index 82eda43c20..843a2c4619 100644
--- a/proto/apl.proto
+++ b/proto/apl.proto
@@ -45,6 +45,7 @@ message APLAction {
     }
 }
 
+// NextIndex: 42
 message APLValue {
     oneof value {
         // Operators
@@ -60,6 +61,7 @@ message APLValue {
         APLValueCurrentTimePercent current_time_percent = 8;
         APLValueRemainingTime remaining_time = 9;
         APLValueRemainingTimePercent remaining_time_percent = 10;
+        APLValueIsExecutePhase is_execute_phase = 41;
         APLValueNumberTargets number_targets = 28;
 
         // Resource values
@@ -104,8 +106,6 @@ message APLValue {
         // Dot values
         APLValueDotIsActive dot_is_active = 6;
         APLValueDotRemainingTime dot_remaining_time = 13;
-
-        // Last Index - 35
     }
 }
 
@@ -217,6 +217,15 @@ message APLValueCurrentTimePercent {}
 message APLValueRemainingTime {}
 message APLValueRemainingTimePercent {}
 message APLValueNumberTargets {}
+message APLValueIsExecutePhase {
+    enum ExecutePhaseThreshold {
+        Unknown = 0;
+        E20 = 1;
+        E25 = 2;
+        E35 = 3;
+    }
+    ExecutePhaseThreshold threshold = 1;
+}
 
 message APLValueCurrentHealth {
     UnitReference source_unit = 1;
diff --git a/sim/core/apl_value.go b/sim/core/apl_value.go
index 6c3d955558..6c229351d1 100644
--- a/sim/core/apl_value.go
+++ b/sim/core/apl_value.go
@@ -68,6 +68,8 @@ func (rot *APLRotation) newAPLValue(config *proto.APLValue) APLValue {
 		return rot.newValueRemainingTime(config.GetRemainingTime())
 	case *proto.APLValue_RemainingTimePercent:
 		return rot.newValueRemainingTimePercent(config.GetRemainingTimePercent())
+	case *proto.APLValue_IsExecutePhase:
+		return rot.newValueIsExecutePhase(config.GetIsExecutePhase())
 	case *proto.APLValue_NumberTargets:
 		return rot.newValueNumberTargets(config.GetNumberTargets())
 
diff --git a/sim/core/apl_values_encounter.go b/sim/core/apl_values_encounter.go
index 9bb3dd5410..29c1b8737e 100644
--- a/sim/core/apl_values_encounter.go
+++ b/sim/core/apl_values_encounter.go
@@ -75,3 +75,31 @@ func (value *APLValueNumberTargets) Type() proto.APLValueType {
 func (value *APLValueNumberTargets) GetInt(sim *Simulation) int32 {
 	return sim.GetNumTargets()
 }
+
+type APLValueIsExecutePhase struct {
+	defaultAPLValueImpl
+	threshold proto.APLValueIsExecutePhase_ExecutePhaseThreshold
+}
+
+func (rot *APLRotation) newValueIsExecutePhase(config *proto.APLValueIsExecutePhase) APLValue {
+	if config.Threshold == proto.APLValueIsExecutePhase_Unknown {
+		return nil
+	}
+	return &APLValueIsExecutePhase{
+		threshold: config.Threshold,
+	}
+}
+func (value *APLValueIsExecutePhase) Type() proto.APLValueType {
+	return proto.APLValueType_ValueTypeBool
+}
+func (value *APLValueIsExecutePhase) GetBool(sim *Simulation) bool {
+	if value.threshold == proto.APLValueIsExecutePhase_E20 {
+		return sim.IsExecutePhase20()
+	} else if value.threshold == proto.APLValueIsExecutePhase_E25 {
+		return sim.IsExecutePhase25()
+	} else if value.threshold == proto.APLValueIsExecutePhase_E35 {
+		return sim.IsExecutePhase35()
+	} else {
+		panic("Should never reach here")
+	}
+}
diff --git a/ui/core/components/individual_sim_ui/apl_values.ts b/ui/core/components/individual_sim_ui/apl_values.ts
index 5d561dba1e..8edf4f857e 100644
--- a/ui/core/components/individual_sim_ui/apl_values.ts
+++ b/ui/core/components/individual_sim_ui/apl_values.ts
@@ -12,6 +12,8 @@ import {
 	APLValueCurrentTimePercent,
 	APLValueRemainingTime,
 	APLValueRemainingTimePercent,
+	APLValueIsExecutePhase,
+	APLValueIsExecutePhase_ExecutePhaseThreshold as ExecutePhaseThreshold,
 	APLValueCurrentHealth,
 	APLValueCurrentHealthPercent,
 	APLValueCurrentMana,
@@ -265,6 +267,23 @@ function mathOperatorFieldConfig(field: string): AplHelpers.APLPickerBuilderFiel
 	};
 }
 
+function executePhaseThresholdFieldConfig(field: string): AplHelpers.APLPickerBuilderFieldConfig<any, any> {
+	return {
+		field: field,
+		newValue: () => ExecutePhaseThreshold.E20,
+		factory: (parent, player, config) => new TextDropdownPicker(parent, player, {
+			...config,
+			defaultLabel: 'None',
+			equals: (a, b) => a == b,
+			values: [
+				{ value: ExecutePhaseThreshold.E20, label: '20%' },
+				{ value: ExecutePhaseThreshold.E25, label: '25%' },
+				{ value: ExecutePhaseThreshold.E35, label: '35%' },
+			],
+		}),
+	};
+}
+
 export function valueFieldConfig(field: string, options?: Partial<AplHelpers.APLPickerBuilderFieldConfig<any, any>>): AplHelpers.APLPickerBuilderFieldConfig<any, any> {
 	return {
 		field: field,
@@ -412,6 +431,15 @@ const valueKindFactories: {[f in NonNullable<APLValueKind>]: ValueKindConfig<APL
 		newValue: APLValueRemainingTimePercent.create,
 		fields: [],
 	}),
+	'isExecutePhase': inputBuilder({
+		label: 'Is Execute Phase',
+		submenu: ['Encounter'],
+		shortDescription: '<b>True</b> if the encounter is in Execute Phase, meaning the target\'s health is less than the given threshold, otherwise <b>False</b>.',
+		newValue: APLValueIsExecutePhase.create,
+		fields: [
+			executePhaseThresholdFieldConfig('threshold'),
+		],
+	}),
 	'numberTargets': inputBuilder({
 		label: 'Number of Targets',
 		submenu: ['Encounter'],