Nick Thomadis, aka Darthmod, used to be one of the most celebrated modders in PC gaming. That was, until he walked away to go and make his own game. From scratch.

For some people, modding is just a hobby. A way to tinker with their favourite games. For others, though, it's a pathway to a career in the video game industry. The experience they pick up working with a particular game, or a particular engine, can see them snapped up by the company that actually owns it.

Thomadis' story is a little different. For years, he'd been a leader in the Total War modding community, his Darthmod upgrades offering sweeping changes and improvements to Creative Assembly's ambitious, but often broken strategy games. While these extensive packs included visual and sound mods from other contributors, it was Thomadis' own work on the game's AI and gameplay that made the biggest difference.

Given the popularity of his mods, and the positive feedback they so often received, Thomadis had hoped the developers of the Total War series, Creative Assembly, would recognise his work and allow him to work more closely with them.

"I passionately loved Creative Assembly products, and dedicated huge amount of time to help make Total War games even better", he tells Kotaku. "Due to Darthmod's popularity I hoped for a closer collaboration with Creative Assembly (as for example Valve closely had cooperated with modders and content creators). This chance never came, my requests for cooperation were officially rejected and CA denied my participation in a modding summit."

Frustrated, he very publicly walked away from the Total War modding community entirely, a move which upset some given the way in which it was handled.

"I felt very disappointed at that time", he says. "I wish though I could return to the past and change my overreaction, because honestly I had great time modding the fantastic Total War games."

Creative Assembly's loss might be PC gaming's gain, though, because Thomadis is taking his experience with the Total War series (and a love of military history) and applying it to a brand new game of his own. It's called Ultimate General: Gettysburg.

An upcoming strategy game set during the famous 1863 battle, it's nothing if not ambitious, given this is Thomadis' first title and he's working with a small team. He's promising an accurate recreation of the actual map, a detailed and authentic order of battle for both armies and "innovative control mechanics".

I'm most interested in the game's AI, though, since that's where the Darthmod packs really excelled. Perhaps put off by Creative Assembly's subtle reliance on the strategy gaming stalwart of "rock paper scissors" (cavalry beats archers, spearmen beats cavalry, infantry beats spearmen, etc) vulnerability, Thomadis is instead programming nine distinct "personalities" that AI generals can assume. Whichever one you're facing will behave according to that personality's preferences, and it's hoped stuff like elevation, morale and fatigue will be the deciding factors in a battle, not unit type.

All of which will be amazing if he can pull it off, but promising things before release and actually delivering them in a working game aren't the same thing, something Thomadis is having to come to grips with.

"There is one major difficulty in professional game development that does not exist in modding", he says. "In modding you have the freedom to make everything as you want with no ultra-strict deadlines and specific commercial goals. In professional design you have limitations in time, resources, and the major responsibility to satisfy the team's and producer's vision for the project's success and sales expectations."

Not that he's particularly worried. "My modding experience helped me to literally learn all the basics about game design and internal game processes", he says. Modding has taught him how to get everything working together in sync without bugs, how to balance gameplay, how to track and fix errors and how to find what players want from their game.

We'll see if he's right when Ultimate General: Gettysburg is released, hopefully later this year. It's currently up for voting on Steam Greenlight.