diff --git a/db/models.py b/db/models.py
index c0bb329..5e966cf 100644
--- a/db/models.py
+++ b/db/models.py
@@ -45,6 +45,15 @@ class Order(BaseModel):
     class Meta:
         table_name = 'order'
 
+class OrderAddOn(BaseModel):
+    name = TextField()
+    probability = FloatField()
+
+    order = ForeignKeyField(column_name='order_id', field='id', model=Order, backref='add_ons')
+
+    class Meta:
+        table_name = 'order_add_on'
+
 #
 # Order State
 #
diff --git a/flask/api.py b/flask/api.py
index fc00969..fd32bc1 100644
--- a/flask/api.py
+++ b/flask/api.py
@@ -1,6 +1,6 @@
 from flask import Blueprint, jsonify, abort, request
 from flask_login import current_user
-from db.models import database, Order
+from db.models import database, Order, OrderAddOn
 from db.queries import user_get, domsubusers_list, orders_pool_list, orders_pool
 
 api = Blueprint('api', __name__)
@@ -51,6 +51,25 @@ def sub_order_set(username, set_id):
   op = orders_pool(sub.id, set_id)
 
   if request.method == 'POST':
+    def update_add_ons(order, add_ons):
+      for updated_add_on in add_ons:
+        if isinstance(updated_add_on['id'], int):
+          add_on_to_update = order.add_ons.where(OrderAddOn.id == updated_add_on['id']).get()
+
+          if '_delete' in updated_add_on:
+            add_on_to_update.delete_instance(recursive=True)
+          else:
+            add_on_to_update.name = updated_add_on['name']
+            add_on_to_update.probability = updated_add_on['probability']
+
+            add_on_to_update.save()
+        else:
+          OrderAddOn.create(
+            order=order,
+            name=updated_add_on['name'],
+            probability=updated_add_on['probability']
+          )
+
     with database.atomic() as transaction:
       try:
         op.name = request.json['name']
@@ -68,6 +87,8 @@ def sub_order_set(username, set_id):
               order_to_update.repeat = updated_order['repeat']
 
               order_to_update.save()
+
+              update_add_ons(order_to_update, updated_order['add_ons'])
           else:
             Order.create(
               pool=op,
@@ -75,8 +96,11 @@ def sub_order_set(username, set_id):
               weight=updated_order['weight'],
               repeat=updated_order['repeat']
             )
+
+            update_add_ons(order_to_update, updated_order['add_ons'])
       except:
         transaction.rollback()
+        abort(500)
 
   return jsonify(
     {
@@ -89,17 +113,11 @@ def sub_order_set(username, set_id):
         'repeat': order.repeat,
         'add_ons': [
           {
-            'id': 1,
-            'name': 'Leg Shackles',
-            'probability': 0.9 
-          },
-          {
-            'id': 2,
-            'name': 'Leather Collar',
-            'probability': 0.5
-          }
+            'id': add_on.id,
+            'name': add_on.name,
+            'probability': add_on.probability 
+          } for add_on in order.add_ons
         ]
       } for order in op.orders]
     }
   )
-
diff --git a/migrations/002_add_order_add_on.py b/migrations/002_add_order_add_on.py
new file mode 100644
index 0000000..8324367
--- /dev/null
+++ b/migrations/002_add_order_add_on.py
@@ -0,0 +1,54 @@
+"""Peewee migrations -- 002_add_order_add_on.py.
+
+Some examples (model - class or model name)::
+
+    > Model = migrator.orm['table_name']            # Return model in current state by name
+    > Model = migrator.ModelClass                   # Return model in current state by name
+
+    > migrator.sql(sql)                             # Run custom SQL
+    > migrator.run(func, *args, **kwargs)           # Run python function with the given args
+    > migrator.create_model(Model)                  # Create a model (could be used as decorator)
+    > migrator.remove_model(model, cascade=True)    # Remove a model
+    > migrator.add_fields(model, **fields)          # Add fields to a model
+    > migrator.change_fields(model, **fields)       # Change fields
+    > migrator.remove_fields(model, *field_names, cascade=True)
+    > migrator.rename_field(model, old_field_name, new_field_name)
+    > migrator.rename_table(model, new_table_name)
+    > migrator.add_index(model, *col_names, unique=False)
+    > migrator.add_not_null(model, *field_names)
+    > migrator.add_default(model, field_name, default)
+    > migrator.add_constraint(model, name, sql)
+    > migrator.drop_index(model, *col_names)
+    > migrator.drop_not_null(model, *field_names)
+    > migrator.drop_constraints(model, *constraints)
+
+"""
+
+from contextlib import suppress
+
+import peewee as pw
+from peewee_migrate import Migrator
+
+
+with suppress(ImportError):
+    import playhouse.postgres_ext as pw_pext
+
+
+def migrate(migrator: Migrator, database: pw.Database, *, fake=False):
+    """Write your migrations here."""
+    
+    @migrator.create_model
+    class OrderAddOn(pw.Model):
+        id = pw.AutoField()
+        name = pw.TextField()
+        probability = pw.FloatField()
+        order = pw.ForeignKeyField(column_name='order_id', field='id', model=migrator.orm['order'])
+
+        class Meta:
+            table_name = "order_add_on"
+
+
+def rollback(migrator: Migrator, database: pw.Database, *, fake=False):
+    """Write your rollback migrations here."""
+    
+    migrator.remove_model('order_add_on')