I get this question fairly often, so I thought I would write up something on my blog about it.  This isn't going to be a complete guide to making your own game or anything, but hopefully it will at least give you some things to think about.

1) My first advice to people that want to make their own game is don't.  Yep, my first piece of advice is don't do it.  Why is this?  Well games (especially RPGs) tend do be way more difficult to make then you would ever imagine, unless you have done it before.  Unless you possess great art, programming, and sound skills, game creating is a team sport.  Do you know anyone that is going to be as passionate as you that will help you create your vision?  Also, if you are trying to make a living making games, creating the game is just the start.  You need to talk to portals and publishers, market the game, and do other little things like run the company.

So my first advice is don't create your own game, get a job at a game company and work there for a couple years so that you get a good look at the full process of making a game.  This way you get a much better understanding of actually creating a game, but you also make lots of good contacts with other people that also want to make games.  If you know that you want to create your own games some day, this is a great opportunity to see what works, what doesn't work, and what you would do differently.  It also helps you see opportunities in the games market that normal developers don't or can't compete in.

2) Now I understand that most people will ignore that piece of advice, so what do you do if you don't want to work for another developer?  I would personally find someone that complements your skills to partner with that is smart, has great drive, and that you can trust.  If you are a programmer find an artist.  If you are an artist find a programmer.  If you find someone that complements you, they will think of things that you never would and they can focus on a different part of the game/company so that you don't have to.  Just make sure to pick someone that will lift you up, not drag you down.

3) For your first game, I would start with something very simple.  With your first game you need the experience of going through the entire process.  Learning the process while doing a complex game is pretty painful.  Also one of the hardest things for indie game creators is actually finishing something.  Many other creative fields have this exact problem.  You actually need to learn how to finish projects.  If you pick something simple for your first project, you will be much more likely to finish it.  Way too many people start something too ambitious and never finish.

4) Once you have picked a project and fleshed out the design some, I would suggest you pick one of the free or cheap game engines that matches as many of the needs of your specific game as possible.  Once you pick an engine, work with the engine not against it.  What I mean by this is don't try to make the engine do things it wasn't designed for.  Try to build a game that it is already capable of.  I have seen teams spend a lot of time and energy, that could have been better spent somwhere else, fighting against the engine instead of working with it.

5) Once you pick an engine the best thing you really can do is start making the game.  The first big obstacle of actually making a game is to get out of the "I want to make a game" process and into the actually building a game process.  Get something playable and fun as quickly as you can.  This is a great motivator to keep moving forward and allows you to play test and polish longer.

Anyways, that's just a little bit of my advice on how to create your own game.  Just for the record, here's what I actually did. Try #1: worked part time at a startup with another programmer for a couple years with our own tech to make an RPG.  So we broke advice 1, 2, 3, and 4. :)  For some reason it didn't work out.  Then I went to work for Ritual for 6 years.  Try #2: After Ritual I started Soldak to make Depths of Peril.  This time I only broke advice 3 and 4 (I did partially luck into #2).  This worked out much better.  Now the question is, what would have happened if I had actually followed all of my advice?