diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 7834c60..e4ae47d 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -5,6 +5,10 @@ class ApplicationController < ActionController::API
 
   before_action :configure_permitted_parameters, if: :devise_controller?
 
+  rescue_from ActionController::ParameterMissing do |e|
+    render json: { error: e.message }, status: :bad_request
+  end
+
   protected
 
   def configure_permitted_parameters
diff --git a/app/controllers/tournaments_controller.rb b/app/controllers/tournaments_controller.rb
index 94e98c0..55143ab 100644
--- a/app/controllers/tournaments_controller.rb
+++ b/app/controllers/tournaments_controller.rb
@@ -4,6 +4,7 @@ class TournamentsController < ApplicationController
   before_action :set_tournament, only: %i[show update destroy]
   before_action :authenticate_user!, only: %i[create update destroy]
   before_action -> { require_owner! @tournament.owner }, only: %i[update destroy]
+  before_action :validate_create_params, only: %i[create]
   rescue_from ActiveRecord::RecordNotFound, with: :render_not_found_error
 
   # GET /tournaments
@@ -71,4 +72,11 @@ class TournamentsController < ApplicationController
   def tournament_params
     params.slice(:name, :description, :public, :teams).permit!
   end
+
+  def validate_create_params
+    teams = params['teams']
+    return if teams.is_a?(Array) && teams.reject { |t| t.is_a? ActionController::Parameters }.count.zero?
+
+    render json: { error: 'Invalid teams array' }, status: :unprocessable_entity
+  end
 end
diff --git a/spec/controllers/tournaments_controller_spec.rb b/spec/controllers/tournaments_controller_spec.rb
index 772a5b3..88d6a6b 100644
--- a/spec/controllers/tournaments_controller_spec.rb
+++ b/spec/controllers/tournaments_controller_spec.rb
@@ -142,6 +142,13 @@ RSpec.describe TournamentsController, type: :controller do
           end.to change(Team, :count).by(data[:teams].count)
         end
       end
+
+      context 'with invalid parameters' do
+        it 'renders an unprocessable entity response' do
+          put :create, params: { teams: [1, 2, 3] }
+          expect(response).to have_http_status(:unprocessable_entity)
+        end
+      end
     end
   end