Obsidian Entertainment - Interview Pt. 3 @ Gamasutra
Gamasutra has the third part of their Chris Avellone interview online:
WO: Fallout 1 and 2 featured low intelligence dialogue – how much extra work does that take? And how fun is it to write; are you able to ‘let loose’ seeing as the more 'serious' playthrough was essentially made redundant when players took this option?
MCA: It takes some work, it's not easy if you're doing the extent it was done in F2 - you have to carefully make sure that all locations are accessible in stupid ways (for example, stupid characters can gain access to Vault City most easily by being enslaved and made a servant, which is another quest path to write and test). This is balanced out by the fact that these quest options and stupid dialogue in general is fun (Torr's subtitles in F2 where you can only "fully" communicate with him as a dumb character). When writing low intelligence dialogue, it's a blast to just sit down, chug a beer or two, and write it. We even wrote all stupid options for every single topic in Dead Money, for example, and that didn't take much time. The problem is, you're still looking at a localization budget, so that's not always feasible, so that needs to be cut even if it may not add to the voice recording time, it'll add to the word count translators need to account for.