Thread: Turning a single player game into multiplayer

I think for my game, I would want the client-server type. The game would run and everyone connects as a client. I think the main thing I need to do is ensure all the clients get the same data to display everything at the same time. Moving from room to room should be easy to send the same information to everyone. But then it gets confusing when you get into combat because there is more data running around.

One advantage of peer to peer is if there are multiple independent groups of players playing that the same time, for example a racing game with many rooms of players in separate lobbies or separate races. The advantage is that you don't end up with all players in all races waiting for server response to update progress. The peer to peer data is usually minimal, such as position, velocity, control input position (use for prediction and also sound), ... . EA made a online racing game called Need For Speed World, based on prior peer to peer based games (including combining the maps from those older games). One issue is that they added powerups to the game which used a server handshake, and this created a delay in response to the powerups, and also caused EA to increase the size of their server farm to deal with all the player activity.

so would it be difficult adding multiplayer into a text based game after it's already created? or would it be easier to start over?

I don't think i have it compartmentalized as much as it should be. As I have been programming it and testing it, I have been finding things I wished I should of done differently but settled with it thinking it's not that bad.

I'm thinking I would like to have a multiplayer that is peer to peer, and you can use your single player character to join up in another single player's world. You can just tell a friend, "Hey, come to my world, I need help beating this guy." Or, "Hey, come to my world, I found a hidden area you need to check out." But that brings in factor's like cheating that I'd like to prevent. Like have a player drop a unique weapon for another player, disconnect, then start up their game with their last saved character. I'm sure I can eventually find a way around that.

I think I will need to find some code that has a good example of input and display being compartmentalized properly. I'm thinking that my code is not.

Even if the actual game play is peer to peer, you will need some way for players to communicate in order to join games, and this is where the client / server interface comes in. Again using past racing games as a model, some of them had a lobby for chat and invites, although if there's a huge number of players this can get hectic. For other racing games, a player indicated he wanted to join a race, and the server would match players together.

While tutoring at a local junior college, where the main computer was an IBM 370, running batch jobs and an interactive programming language called APL. When the APL got upgraded to APL SV (shared variables) which allowed terminal to terminal communication, they had battleship board type game up and running within a week. There were some graphic terminals, and they later got a space wars type game up and running on those.