11-bit Studios' This War Of Mine managed to impress when it first arrived last year and the game has continued to power on since then. In fact, it just hit version 2.0 which, along with all the expected fixes and tweaks that comes with patch, has introduced modding tools for tinkering enthusiasts.
The video above goes into details about what's possible, but there's a rather short blog post on the developer's website that provides the Cliff-Cliff-Cliff Notes on what you can expect:
Modding Tools Features - creating and editing scenarios - creating and editing items - creating and editing crafting recipies - creating and editing weapons - creating and editing visits - adding custom sounds and music
So lots of creating and editing and that thing about audio effects. Sounds good!
The developer mentions the tools are "late", but it doesn't appear as though the delay had much of an impact on the game's success.