FRUA is a Gold Box engine construction kit, released in '93, sort of a precursor to Neverwinter Nights (but better — turn-based combat!) that's still active today (and seeing some of its best releases even now).
In order to play it you need to have UAShell
The easiest way to run it in DOSBox is to just extract frua1.2crk.rar, open the folder “frua” inside of it, extract uashellc into it, put a shortcut to DOSBox in the same folder and drag and drop uashell.bat onto the DOSBox shortcut. that should apply it to FRUA. and then to play either just drag and drop uashell.bat on the shortcut again or alter the DOSBox shortcut target to open it automatically