diff --git a/battleship/utils.py b/battleship/utils.py
new file mode 100644
index 0000000..3911257
--- /dev/null
+++ b/battleship/utils.py
@@ -0,0 +1,55 @@
+def check_field(field):
+    if field.count('o') != 20:
+        return False
+    cells = list(field)
+    cells = [cells[x * 10: (x + 1) * 10] for x in range(0, 10)]
+    ships = [1, 1, 1, 1, 2, 2, 2, 3, 3, 4]
+    while ships:
+        found = False
+        for i in range(10):
+            for j in range(10):
+                if cells[i][j] == 'o':
+                    i1, j1 = i, j
+                    if j1 == 9 or cells[i1][j1 + 1] == ' ':  # если вертикальный
+                        if i1 == 9 or cells[i1 + 1][j1] == ' ':  # если 1 палуба
+                            p = 1
+                        elif i1 + 1 == 9 or cells[i1 + 2][j1] == ' ':  # если 2 палубы
+                            p = 2
+                        elif i1 + 2 == 9 or cells[i1 + 3][j1] == ' ':  # если 3 палубы
+                            p = 3
+                        elif i1 + 3 != 9 and cells[i1 + 4][j1] == 'o':
+                            return False
+                        else:
+                            p = 4
+                        if p in ships:
+                            ships.remove(p)
+                        else:
+                            return False
+                        for k in range(p):
+                            cells[i1 + k][j1] = ' '
+                    else:
+                        if j1 == 9 or cells[i1][j1 + 1] == ' ':  # если 1 палуба
+                            p = 1
+                        elif j1 + 1 == 9 or cells[i1][j1 + 2] == ' ':  # если 2 палубы
+                            p = 2
+                        elif j1 + 2 == 9 or cells[i1][j1 + 3] == ' ':  # если 3 палубы
+                            p = 3
+                        elif j1 + 3 != 9 and cells[i1][j1 + 4] == 'o':
+                            return False
+                        else:
+                            p = 4
+                        if p in ships:
+                            ships.remove(p)
+                        else:
+                            return False
+                        for k in range(p):
+                            cells[i1][j1 + k] = ' '
+                    found = True
+                if found:
+                    break
+            if found:
+                break
+        if not found:
+            return False
+
+    return True
diff --git a/battleship/views.py b/battleship/views.py
index 29630c6..854abc6 100644
--- a/battleship/views.py
+++ b/battleship/views.py
@@ -5,6 +5,7 @@ from django.shortcuts import render
 from django.utils import timezone
 
 from battleship.models import Game, Player, generate_token
+from battleship.utils import check_field
 
 
 def new_game(request):
@@ -45,8 +46,11 @@ def place_ships(request):
     if player.field != ' ' * 100:
         return JsonResponse({}, status=403)
     player.field = request.POST['field']
-    player.save()
-    return JsonResponse({})
+    if check_field(player.field):
+        player.save()
+        return JsonResponse({})
+    else:
+        return JsonResponse({}, status=403)
 
 
 def check_opponent(request):
diff --git a/requirements.txt b/requirements.txt
index 08cdb6f..6e91de7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,16 @@
 asgiref==3.5.2
+attrs==22.1.0
 Django==3.2.15
+importlib-metadata==4.12.0
+iniconfig==1.1.1
+packaging==21.3
+pluggy==1.0.0
 psycopg2==2.9.3
+py==1.11.0
+pyparsing==3.0.9
+pytest==7.1.2
 pytz==2022.2.1
 sqlparse==0.4.2
+tomli==2.0.1
 typing_extensions==4.3.0
+zipp==3.8.1
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_check_field.py b/tests/test_check_field.py
new file mode 100644
index 0000000..3dd4186
--- /dev/null
+++ b/tests/test_check_field.py
@@ -0,0 +1,55 @@
+from battleship.utils import check_field
+
+
+def test_simple():
+    field = [
+        ['o', 'o', 'o', 'o', ' ', 'o', 'o', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+    ]
+    field = [''.join(a) for a in field]
+    field = ''.join(field)
+    assert check_field(field)
+
+
+def test_incorrect():
+    field = [
+        ['o', ' ', 'o', 'o', ' ', 'o', 'o', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+    ]
+    field = [''.join(a) for a in field]
+    field = ''.join(field)
+    assert not check_field(field)
+
+
+def test_incorrect2():
+    field = [
+        ['o', 'o', 'o', 'o', ' ', 'o', 'o', 'o', ' ', 'o'],
+        [' ', ' ', 'o', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', 'o', ' ', ' ', 'o', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', ' '],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o'],
+        [' ', ' ', ' ', ' ', ' ', ' ', ' ', 'o', ' ', 'o'],
+    ]
+    field = [''.join(a) for a in field]
+    field = ''.join(field)
+    assert not check_field(field)