How to make a game where i can log in always?

Unity Engine
1

Sorry, becouse english is not my main language i have problems to explain it the way i want.

I want to make a prototype for an multiplayer rpg game where for example a friend can log in at everytime in the game to play with me together.

So normal you have to choose to play a game in single or multiplayer but i want the game to be allways a multiplayer game but can be played like a single player game.

So besides some other problems i thought that i want that the player should choose a password at the beginning of the game and then for example he can tell his ip adress and the password to his friend and he that way can log in the game as long as the ip do not have changed.

Also i am not so good at coding with c# and even less good at network coding i want to archieve something like that so i want to aks for some general thought, not the working code.

I start to learn unitys own network code with some assets i bought in the store and some tutorials from youtube and the network gtgt tutorials.

2

Make the game fully multiplayer, then simply give the option to play single player and not show other players in the game, etc. Still handle everything server sided, but just don’t send data to the client relating to other players.