The new frontier... The perils of the unknown... The great difficulties and the great hope for the next generation? No, I'm not talking about colonizing Mars. I'm talking about the greatest technical risk we took on with Surviving Mars: building the game for modding support.
Haemimont Games has shipped a cool 15 games on various platforms, but not one of them has had official modding support. And modding was something Paradox wanted from the very beginning of the project. Games that welcome the players to join in the creation are loved more, played more, and live more, they said. What's the point of partnering with a well-respected experienced publisher if you don't heed what they say?
The bad news was that over the previous several games, the data loading process of our engine had been optimized in the opposite direction, to be as monolithic and economical as possible, to allow for minimal loading times. This had to be reversed, and many types of data can now be loaded in pieces, or late after the game has started, to allow for asset authoring and tested.
The good and much more important news was that our games are written in a mixture of two programming languages: C++ to handle the low-level stuff like graphics, audio and talking to the underlying hardware; Lua. Which allowed us to implement virtually everything you think of as "game", from the simulation logic of the colonists on Mars to the user interface that allows the player to control them. And Lua is not only much easier for modders to learn - it's also easy to be loaded from different places, even when the game is running. We knew that we needed to give modders this ultimate power, to modify and add new Lua code to the game.
The overarching goal of the mod support is, in the words of Alan Kay, simple things should be simple, and complex things should be possible. For the simple part, we identified a handful of small but impactful changes to the game that can be implemented by anyone who's not afraid of their computer. Mission Logos, for example, let you leave your imprint on every building of your colony. You only need to supply a simple, transparent PNG file
You can read the full dev diary here