app/models/user.rb
class User < ApplicationRecord
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
has_many :game_players, dependent: :destroy
has_many :games, through: :game_players
end