diff --git a/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java b/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java
index b0624b4..e00dddd 100644
--- a/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java
+++ b/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java
@@ -6,6 +6,7 @@ import com.magistr.app.dto.ScheduleRuleSlotDto;
 import com.magistr.app.model.*;
 import com.magistr.app.repository.*;
 import com.magistr.app.service.ScheduleGeneratorService;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.bind.annotation.*;
@@ -81,6 +82,13 @@ public class ScheduleRuleAdminController {
         try {
             ScheduleRule rule = new ScheduleRule();
             applyRule(rule, request);
+            ScheduleRule conflictRule = findConflictingRule(request, rule.getSlots(), null);
+            if (conflictRule != null) {
+                return ResponseEntity.status(HttpStatus.CONFLICT).body(Map.of(
+                        "message", "Невозможно сохранить правило: слот занят",
+                        "conflictRule", toDto(conflictRule)
+                ));
+            }
             ScheduleRule saved = scheduleRuleRepository.save(rule);
             scheduleGeneratorService.clearCache();
             return ResponseEntity.ok(toDto(saved));
@@ -104,6 +112,13 @@ public class ScheduleRuleAdminController {
 
         try {
             applyRule(rule, request);
+            ScheduleRule conflictRule = findConflictingRule(request, rule.getSlots(), rule.getId());
+            if (conflictRule != null) {
+                return ResponseEntity.status(HttpStatus.CONFLICT).body(Map.of(
+                        "message", "Невозможно сохранить правило: слот занят",
+                        "conflictRule", toDto(conflictRule)
+                ));
+            }
             ScheduleRule saved = scheduleRuleRepository.save(rule);
             scheduleGeneratorService.clearCache();
             return ResponseEntity.ok(toDto(saved));
@@ -181,6 +196,37 @@ public class ScheduleRuleAdminController {
         rule.getSlots().addAll(slots);
     }
 
+    private ScheduleRule findConflictingRule(ScheduleRuleDto request, Collection<ScheduleRuleSlot> newSlots, Long excludeRuleId) {
+        return scheduleRuleRepository.findAllWithDetails().stream()
+                .filter(rule -> !Objects.equals(rule.getId(), excludeRuleId))
+                .filter(rule -> rule.getSemester() != null && Objects.equals(rule.getSemester().getId(), request.semesterId()))
+                .filter(rule -> hasSlotConflict(newSlots, rule.getSlots()))
+                .min(Comparator.comparing(ScheduleRule::getId))
+                .orElse(null);
+    }
+
+    private boolean hasSlotConflict(Collection<ScheduleRuleSlot> newSlots, Collection<ScheduleRuleSlot> existingSlots) {
+        for (ScheduleRuleSlot newSlot : newSlots) {
+            for (ScheduleRuleSlot existingSlot : existingSlots) {
+                if (sameTimeSlot(newSlot, existingSlot) && sameTeacherOrClassroom(newSlot, existingSlot)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    private boolean sameTimeSlot(ScheduleRuleSlot first, ScheduleRuleSlot second) {
+        return Objects.equals(first.getDayOfWeek(), second.getDayOfWeek())
+                && Objects.equals(first.getParity(), second.getParity())
+                && Objects.equals(first.getTimeSlot().getId(), second.getTimeSlot().getId());
+    }
+
+    private boolean sameTeacherOrClassroom(ScheduleRuleSlot first, ScheduleRuleSlot second) {
+        return Objects.equals(first.getTeacher().getId(), second.getTeacher().getId())
+                || Objects.equals(first.getClassroom().getId(), second.getClassroom().getId());
+    }
+
     private ScheduleRuleSlot buildSlot(ScheduleRule rule, ScheduleRuleSlotDto slotDto) {
         if (slotDto.dayOfWeek() == null || slotDto.dayOfWeek() < 1 || slotDto.dayOfWeek() > 7) {
             throw new IllegalArgumentException("День недели должен быть от 1 до 7");