diff --git a/components/ILIAS/Conditions/classes/class.ilConditionHandlerGUI.php b/components/ILIAS/Conditions/classes/class.ilConditionHandlerGUI.php
index 335ba5cce035..2d0c8d325289 100755
--- a/components/ILIAS/Conditions/classes/class.ilConditionHandlerGUI.php
+++ b/components/ILIAS/Conditions/classes/class.ilConditionHandlerGUI.php
@@ -1,7 +1,5 @@
 <?php
 
-declare(strict_types=1);
-
 /**
  * This file is part of ILIAS, a powerful learning management system
  * published by ILIAS open source e-Learning e.V.
@@ -18,6 +16,8 @@
  *
  *********************************************************************/
 
+declare(strict_types=1);
+
 use ILIAS\Refinery\Factory;
 use ILIAS\HTTP\GlobalHttpState;
 use ILIAS\Conditions\Configuration\ConditionTriggerTableGUI;
@@ -893,9 +893,10 @@ protected function initCompulsoryForm(bool $with_request = false): ?StandardForm
             $this->getTargetId(),
             $this->getTargetType()
         );
+        $is_subset_mode = count($optional_conditions) > 0;
 
         $old_status = $this->ui_factory->input()->field()->hidden()->withValue(
-            (string) (count($optional_conditions) ? self::LIST_MODE_SUBSET : self::LIST_MODE_ALL)
+            (string) ($is_subset_mode ? self::LIST_MODE_SUBSET : self::LIST_MODE_ALL)
         );
 
         $hidden = $this->ui_factory->input()->field()->checkbox(
@@ -911,30 +912,50 @@ protected function initCompulsoryForm(bool $with_request = false): ?StandardForm
         $list_mode_items[self::LIST_MODE_ALL] = $condition_mode_all;
 
         $subset_limit = [];
-        if (count($all_conditions) > 1) {
+        $compulsory_count = 0;
+        foreach ($all_conditions as $condition) {
+            if ($condition['obligatory']) {
+                $compulsory_count++;
+            }
+        }
+
+        $all_conditions_number = count($all_conditions);
+        if ($all_conditions_number > 1) {
 
             $num_required = ilConditionHandler::lookupObligatoryConditionsOfTarget(
                 $this->getTargetRefId(),
                 $this->getTargetId()
             );
-            $subset_limit['num_compulsory'] =
-                $this->ui_factory->input()
-                                 ->field()
-                                 ->numeric(
-                                     $this->lng->txt('precondition_num_obligatory'),
-                                     $this->lng->txt('precondition_num_optional_info')
-                                 )
-                                 ->withValue($num_required > 0 ? $num_required : null)
-                                 ->withAdditionalTransformation(
-                                     $this->refinery->logical()->parallel(
-                                         [
-                                             $this->refinery->int()->isGreaterThan(0),
-                                             $this->refinery->int()->isLessThan(count($all_conditions))
-                                         ]
-                                     )
-                                 );
-        }
-        if (count($all_conditions) > 1) {
+            $subset_limit['num_compulsory'] = $this->ui_factory->input()->field()
+                ->numeric(
+                    $this->lng->txt('precondition_num_obligatory'),
+                    $this->lng->txt('precondition_num_optional_info')
+                )
+                ->withValue($num_required > 0 ? $num_required : null)
+                ->withAdditionalTransformation(
+                    $this->refinery->custom()->constraint(
+                        fn($val) => $val >= 1,
+                        $this->lng->txt('precondition_number_of_required_materials_lower_than_one')
+                    )
+                )
+                // check if the number of required materials is bigger than compulsory conditions in subset mode
+                ->withAdditionalTransformation(
+                    $this->refinery->custom()->constraint(
+                        function ($val) use ($is_subset_mode, $compulsory_count) {
+                            if ($is_subset_mode) {
+                                return $val >= $compulsory_count + 1;
+                            }
+                            return true;
+                        },
+                        $this->lng->txt('precondition_number_of_required_materials_lower_compulsory_items')
+                    )
+                )
+                ->withAdditionalTransformation(
+                    $this->refinery->custom()->constraint(
+                        fn($val) => $val <= $all_conditions_number - 1,
+                        $this->lng->txt('precondition_number_of_required_materials_bigger_preconditions_number')
+                    )
+                );
             $condition_mode_subset = $this->ui_factory->input()->field()->group(
                 $subset_limit,
                 $this->lng->txt('rbac_precondition_mode_subset'),
diff --git a/lang/ilias_de.lang b/lang/ilias_de.lang
index 436d20c6b345..15d9d77e9a82 100644
--- a/lang/ilias_de.lang
+++ b/lang/ilias_de.lang
@@ -14516,6 +14516,9 @@ rbac#:#positions_override_operations#:#Globale Einstellungen überschreiben
 rbac#:#precondition_not_obligatory_alt#:#Die Vorbedingung ist optional
 rbac#:#precondition_num_obligatory#:#Geforderte Anzahl Materialien
 rbac#:#precondition_num_optional_info#:#Anzahl von Materialien, die bis zum festgelegten Status / Ergebnis zu bearbeiten sind
+rbac#:#precondition_number_of_required_materials_bigger_preconditions_number#:#Die Anzahl der geforderten Materialien muss kleiner sein als die Anzahl der Vorbedingungen.
+rbac#:#precondition_number_of_required_materials_lower_compulsory_items#:#Die Anzahl der geforderten Materialien muss größer sein als die Anzahl der verpflichtenden Vorbedingungen.
+rbac#:#precondition_number_of_required_materials_lower_than_one#:#Die Anzahl der geforderten Materialien muss mindestens 1 sein.
 rbac#:#precondition_obligatory#:#Verpflichtend
 rbac#:#precondition_obligatory_alt#:#Die Vorbedingung muss erfüllt werden
 rbac#:#precondition_obligatory_info#:#Verpflichtende Vorbedingungen müssen erfüllt werden, um Zugriff zu erhalten.
diff --git a/lang/ilias_en.lang b/lang/ilias_en.lang
index d6f95bdc77e3..bf5795101e75 100755
--- a/lang/ilias_en.lang
+++ b/lang/ilias_en.lang
@@ -14517,6 +14517,9 @@ rbac#:#positions_override_operations#:#Override global Settings
 rbac#:#precondition_not_obligatory_alt#:#Precondition is optional
 rbac#:#precondition_num_obligatory#:#Number of Required Materials
 rbac#:#precondition_num_optional_info#:#Please enter the minimum number of materials required to fulfill this precondition.
+rbac#:#precondition_number_of_required_materials_bigger_preconditions_number#:#The number of required materials must be less than the total number of preconditions.
+rbac#:#precondition_number_of_required_materials_lower_compulsory_items#:#The number of required materials must be greater than the number of compulsory preconditions.
+rbac#:#precondition_number_of_required_materials_lower_than_one#:#The number of required materials must be at least 1.
 rbac#:#precondition_obligatory#:#Compulsory
 rbac#:#precondition_obligatory_alt#:#Precondition must be fulfilled
 rbac#:#precondition_obligatory_info#:#Compulsory preconditions must be fulfilled, for having access.