diff --git a/tests/tasks/bt_test_action.h b/tests/tasks/bt_test_action.h
index 25a8721..e18104d 100644
--- a/tests/tasks/bt_test_action.h
+++ b/tests/tasks/bt_test_action.h
@@ -17,10 +17,8 @@
 class BTTestAction : public BTAction {
 	GDCLASS(BTTestAction, BTAction);
 
-private:
-	int ret_status = BTTask::SUCCESS;
-
 public:
+	int ret_status = BTTask::SUCCESS;
 	int num_entries = 0;
 	int num_ticks = 0;
 	int num_exits = 0;
diff --git a/tests/test_selector.h b/tests/test_selector.h
new file mode 100644
index 0000000..b8fe5bc
--- /dev/null
+++ b/tests/test_selector.h
@@ -0,0 +1,198 @@
+/**
+ * test_selector.h
+ * =============================================================================
+ * Copyright 2021-2023 Serhii Snitsaruk
+ *
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ * =============================================================================
+ */
+
+#ifndef TEST_SELECTOR_H
+#define TEST_SELECTOR_H
+
+#include "tests/test_macros.h"
+
+#include "modules/limboai/bt/tasks/bt_task.h"
+#include "modules/limboai/bt/tasks/composites/bt_selector.h"
+#include "modules/limboai/tests/tasks/bt_test_action.h"
+
+namespace TestSelector {
+
+TEST_CASE("[Modules][LimboAI] BTSelector when all return FAILURE") {
+	Ref<BTSelector> sel = memnew(BTSelector);
+	Ref<BTTestAction> task1 = memnew(BTTestAction(BTTask::FAILURE));
+	Ref<BTTestAction> task2 = memnew(BTTestAction(BTTask::FAILURE));
+	Ref<BTTestAction> task3 = memnew(BTTestAction(BTTask::FAILURE));
+
+	sel->add_child(task1);
+	sel->add_child(task2);
+	sel->add_child(task3);
+
+	REQUIRE(sel->get_child_count() == 3);
+
+	// * First execution.
+	CHECK(sel->execute(0.1666) == BTTask::FAILURE);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::FAILURE);
+	CHECK(task3->get_status() == BTTask::FAILURE);
+
+	CHECK(task1->num_entries == 1);
+	CHECK(task1->num_ticks == 1);
+	CHECK(task1->num_exits == 1);
+
+	CHECK(task2->num_entries == 1);
+	CHECK(task2->num_ticks == 1);
+	CHECK(task2->num_exits == 1);
+
+	CHECK(task3->num_entries == 1);
+	CHECK(task3->num_ticks == 1);
+	CHECK(task3->num_exits == 1);
+
+	// * Second execution.
+	CHECK(sel->execute(0.1666) == BTTask::FAILURE);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::FAILURE);
+	CHECK(task3->get_status() == BTTask::FAILURE);
+
+	CHECK(task1->num_entries == 2);
+	CHECK(task1->num_ticks == 2);
+	CHECK(task1->num_exits == 2);
+
+	CHECK(task2->num_entries == 2);
+	CHECK(task2->num_ticks == 2);
+	CHECK(task2->num_exits == 2);
+
+	CHECK(task3->num_entries == 2);
+	CHECK(task3->num_ticks == 2);
+	CHECK(task3->num_exits == 2);
+}
+
+TEST_CASE("[Modules][LimboAI] BTSelector when second returns SUCCESS") {
+	Ref<BTSelector> sel = memnew(BTSelector);
+	Ref<BTTestAction> task1 = memnew(BTTestAction(BTTask::FAILURE));
+	Ref<BTTestAction> task2 = memnew(BTTestAction(BTTask::SUCCESS));
+	Ref<BTTestAction> task3 = memnew(BTTestAction(BTTask::FAILURE));
+
+	sel->add_child(task1);
+	sel->add_child(task2);
+	sel->add_child(task3);
+
+	REQUIRE(sel->get_child_count() == 3);
+
+	// * First execution.
+	CHECK(sel->execute(0.1666) == BTTask::SUCCESS);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::SUCCESS);
+	CHECK(task3->get_status() == BTTask::FRESH);
+
+	CHECK(task1->num_entries == 1);
+	CHECK(task1->num_ticks == 1);
+	CHECK(task1->num_exits == 1);
+
+	CHECK(task2->num_entries == 1);
+	CHECK(task2->num_ticks == 1);
+	CHECK(task2->num_exits == 1);
+
+	CHECK(task3->num_entries == 0);
+	CHECK(task3->num_ticks == 0);
+	CHECK(task3->num_exits == 0);
+
+	// * Second execution.
+	CHECK(sel->execute(0.1666) == BTTask::SUCCESS);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::SUCCESS);
+	CHECK(task3->get_status() == BTTask::FRESH);
+
+	CHECK(task1->num_entries == 2);
+	CHECK(task1->num_ticks == 2);
+	CHECK(task1->num_exits == 2);
+
+	CHECK(task2->num_entries == 2);
+	CHECK(task2->num_ticks == 2);
+	CHECK(task2->num_exits == 2);
+
+	CHECK(task3->num_entries == 0);
+	CHECK(task3->num_ticks == 0);
+	CHECK(task3->num_exits == 0);
+}
+
+TEST_CASE("[Modules][LimboAI] BTSelector when second returns RUNNING") {
+	Ref<BTSelector> sel = memnew(BTSelector);
+	Ref<BTTestAction> task1 = memnew(BTTestAction(BTTask::FAILURE));
+	Ref<BTTestAction> task2 = memnew(BTTestAction(BTTask::RUNNING));
+	Ref<BTTestAction> task3 = memnew(BTTestAction(BTTask::FAILURE));
+
+	sel->add_child(task1);
+	sel->add_child(task2);
+	sel->add_child(task3);
+
+	REQUIRE(sel->get_child_count() == 3);
+
+	// * First execution.
+	CHECK(sel->execute(0.1666) == BTTask::RUNNING);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::RUNNING);
+	CHECK(task3->get_status() == BTTask::FRESH);
+
+	CHECK(task1->num_entries == 1);
+	CHECK(task1->num_ticks == 1);
+	CHECK(task1->num_exits == 1);
+
+	CHECK(task2->num_entries == 1);
+	CHECK(task2->num_ticks == 1);
+	CHECK(task2->num_exits == 0);
+
+	CHECK(task3->num_entries == 0);
+	CHECK(task3->num_ticks == 0);
+	CHECK(task3->num_exits == 0);
+
+	// * Second execution.
+	CHECK(sel->execute(0.1666) == BTTask::RUNNING);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::RUNNING);
+	CHECK(task3->get_status() == BTTask::FRESH);
+
+	CHECK(task1->num_entries == 1);
+	CHECK(task1->num_ticks == 1);
+	CHECK(task1->num_exits == 1);
+
+	CHECK(task2->num_entries == 1);
+	CHECK(task2->num_ticks == 2);
+	CHECK(task2->num_exits == 0);
+
+	CHECK(task3->num_entries == 0);
+	CHECK(task3->num_ticks == 0);
+	CHECK(task3->num_exits == 0);
+
+	// * Third execution with second task returning FAILURE.
+	task2->ret_status = BTTask::FAILURE;
+	CHECK(sel->execute(0.1666) == BTTask::FAILURE);
+
+	CHECK(task1->get_status() == BTTask::FAILURE);
+	CHECK(task2->get_status() == BTTask::FAILURE);
+	CHECK(task3->get_status() == BTTask::FAILURE);
+
+	CHECK(task1->num_entries == 1);
+	CHECK(task1->num_ticks == 1);
+	CHECK(task1->num_exits == 1);
+
+	CHECK(task2->num_entries == 1);
+	CHECK(task2->num_ticks == 3);
+	CHECK(task2->num_exits == 1);
+
+	CHECK(task3->num_entries == 1);
+	CHECK(task3->num_ticks == 1);
+	CHECK(task3->num_exits == 1);
+}
+
+} //namespace TestSelector
+
+#endif // TEST_SELECTOR_H