I'm graduating from American University, in Washington DC. I came here to study international relations, but then realized I was more compelled by video game design.
I did a few important things to prepare myself for a job in the games industry that have paid off a lot.
First, I picked up a CS minor. Because I can program games myself (admittedly simple ones) I'm not dependent on anyone else to start making a prototype when I have an idea for a game I want to make. For example, I just made a little game for this contest
almost totally by myself. Finding someone willing to work equally hard as you on a project can be pretty difficult, especially on short notice, which my entry into this contest was. Being forced to rely on someone, ie a programmer, that isn't as committed to the project as you are really sucks because you'll end up forcing them to do things they don't want to do, and it won't be fun. If you can program the game yourself you dont have to worry about that as often.
I've entered a few other contests with little games I've made myself. I've definitely learned some of the pitfalls of game development by making these little games myself, so I'm very glad I learned how to program.
One other smart thing I did was get involved with my local IGDA chapter. I've met lot of cool dudes through there. I've worked with a few of them on projects, which was good experience. I also wouldn't be surprised at all if at some point I get a job through one of them.
The last important thing I did was go to game jams. Have you heard of the Global Game Jam? google it. Always make time for things like this. A lot of game developers still trying to make it will tell you how many unfinished projects they have. Usually we don't finish because we don't have to, and we get lazy. But game jams give you a deadline and motivate you to finish. Oftentimes people end up with nice little portfolio projects at the end of them.
But your main question was what gives me the confidence to work in the industry.
Originally, I thought I would be a successful game designer because I thought my ideas were better than most people's. I assumed I would be able to make games that were revolutionary and would blow people's pants off. And somehow my ability with ideas would get me a job or something. I wasn't really sure. But luckily I took people's advice on this very forum and learned to program : )
It turns out it takes a lot of work and discipline to make a game, even a small one. And if you can't do that, then no one will ever see your awesome ideas.
There are a lot of lessons to learn about working with people and intelligently managing yourself and your project you have to learn to make the game in your head. If you don't have that experience, something will go wrong and your game won't end up being what you want it to be. At least in my experience. The biggest example of what I'm talking about being the scope problem. Everyone tries to make their first game way larger than it should be, and they fail. Happened to me.
Another example: my entry for this contest is not as intuitive as it should be because I didn't look up from the code often enough to analyze if what I was making was really what the contest called for. I spent hours and hours coding complicated systems so I could have online multiplayer before I realized that the only way that multiplayer would be used was if the judges all logged on at the same time, which isn't going to happen. I ended up scrapping the real multiplayer because it was taking too long to add stuff, and faked it with AI. That was a lot of time wasted that should have went towards making what my game is about more obvious. Lesson learned: constantly reevaluate if what you're working on is really necessary to what you're trying to accomplish.
To finally answer your question: my confidence comes from me knowing that as I continue to make games I will continue to learn these lessons, and eventually be a good/great game developer. I couldn't say right now with confidence that someone should hire me as a game designer. That's why I'm probably going to get a non-games related programming job at first (again being saved by the CS minor). But eventually I think I'll be able to make a living from games in some form or another.
If I knew any level designers with jobs, I would put you in contact with them. But I don't : \
My demo for that contest is online here
if you're curious. The contest tasked us with re-imagining Pong, so I made it a spectator sport. Two teams play each other in 1v1 matches, and as people lose they become spectators. Eventually a bunch of people are watching a single match, which is exciting for those people playing. I got the idea from Counter Strike.