Arma has always been a modders paradise, though I imagine the mad success of DayZ has prompted Bohemia to encourage the practice even more. Thus, the Make Arma Not War contest. By producing content in one of four categories - Total Modiciation, Singleplayer Game Mode, Multiplayer Game Mode and Add-on - modders can win part of a prize pool of €500,000. If your project shows potential and regardless of whether or not you win, Bohemia might be in touch to offer you a development contract.
Details and an introductory video below.
Winners of the Total Modification category will receive €200,000, while prize money for the other categories is divided between 1st place (€50,000), 2nd place (€30,000), and 3rd place (€20,000).
The contest is also being held in partnership with the Red Cross. Entrants who best cover the topic "health care in danger" will be in with a chance to win a special award and a one-week trip to a Red Cross mission in a foreign country, organized by the ICRC.
If you'd like to enter, there's no need to rush. Applications won't open until next year, and the closing date for the competition is October 28, 2014. That gives you plenty of time to get to grips with Arma 3's mod tools and start on your project. I've already begun work on my own entry, about the later life of two wartime friends. It's called ZayD.
That was torturous, but check out more details on the official Make Arma Not War site.