Developing singleplayer around multiplayer?

My friend and I are making a game. This game is multi-player oriented (singleplayer is necessary but will be used little)

Would it be a good idea to create the game as multiplayer first, then have singleplayer just be a local server that only you can enter?

It all depends on your game but there are commercial games that does this (or seems to do this attest). Garry’s Mod for example.

But if you design your game nicely you could avoid this. With a good design you should be able to attach a “localserver” or a client to the game.

The client should talk network like normal and the localserver should use the same interface as the client but everything should be done locally without network. Both the server and the localserver should use the same classes that does the real logic.

Really depends on the game. Usually when I buy games I just go with…

If I want SP I’ll buy a SP game

If I want MP I’l buy a MP game…

Not sure if you really need SP… mostly if its only the same game just without MP. A perfect example would be Battlefield: Bad Company… the whole SP campaign just felt like a bunch of MP maps stiched together with a couple of cutscenes trying to resemble a SP expierience. It was playable, but neither memorable or good…

It’s really hard to answer that question when we have no idea what the game is about and how it will play.

More options are probably a good thing so nothing agaisnt doing this… there will certainly be someone who will appreciate it if you do decide to do it. You just have to figure out if its actually going to work and if its worth the time… (assuing that it actually takes a lot of time to do)