I dunno. It would take too long to list all the ones I worked on, by the end of W3 I probably worked on two or three dozen quests. When I was brought on to W3 in the last couple years of development, I was originally working on a big quest chain with a seperate team of writers and designers. That quest chain was eventually cut for reasons. The only remainders of that quest chain still around are Eye for an Eye, Blood Ties, and Contract: Patrol Gone Missing. Eye for an Eye was also hugely trimmed down, it used to be a lot bigger.
Other than those three, the quests in W3 I was most involved with (though didn't originally design) are: Funeral Pyres, Ghosts of the Past/Fall of the House of Reardon, Fencing Lessons, The Aparian Phantom, Muire D'Yaeblen, Tower Outta Nowhere, and Fool's Gold.
I was assigned to BaW and not HoS, but I still designed and implemented The Taxman Cometh, and Rose on a Red Field, the latter of which I'm not particularly happy with how it turned out, but it was designed and implemented in just a couple of days, so that's something I guess.
BaW, I designed/implemented: Equine Phantoms, Feet Cold as Ice, also worked a bunch on Till Death Do You Part and A Knight's Tales. My big quest here got cut for production, it took place in Fox Hollow and involved genocide, ya'll would have liked it. Also I had a troll quest that was great but the director didn't think it was funny so it got shot into space.
Yeah, he [Iorveth] was in the base game but got cut for reasons. He just never made sense for the expansions or DLC for other reasons. His previous role in the game was in a quest chain that eventually became the basis for Hearts of Stone, but between the initial implementation (for W3) and the full expansion (HoS) it was totally rewritten, to the point that you wouldn't recognize the quest at all. It was a story about the Catriona plague, Mr. Mirror, and some Nilfgaardian researchers. Maybe after we're all done with the game I can drop some more details, the cut stuff with Iorveth was mostly my stuff, so it makes me sad we never got to use him.
I think one of my big disappointments with some of the cut content in W3 is that we lost a lot of the darker shadings on the Nilfgaardians. The cut stuff wasn't the same quality as the rest of the game and there's no way we'd have had the time to finish it, but the Nilfgaardians do some pretty heinous shit in the name of law & order. Yeah, they create order and prosperity, but what is that worth to the people they crush to get there? Wealth and rule of law are pretty pointless when a significant portion of your population have no (or at least very limited) access to either.
Originally Iorveth showed up on Velen searching for a cure to a plague ravaging the south, including Mahakam. Geralt has to team up with Iorveth, and Roche, Ves, and Thaler for very complicated reasons to try and get this cure. The whole plague plotline mostly got cut, though there's some elements of it drifting around in places, like the guy with the corpse wagon who claims he's immune. The quest where you have to get Ves out of the fight with the Nilfgaardians was also part of this plotline, though in a substantially different form (I think the cuts and rewrites really hurt her character, sadly. )
In the version of her quest that I liked best, she's pissed off because the village of Poppystone helped the Partisans escape Velen, but the Nilfs found out about it and are going to execute some people. Ves asks Geralt to help her liberate them behind Roche's back. Ves and Geralt go, save some folks and kill some Nilfgaardians, they have a really nice scene together where they talk about constellations and elven mythology, then go back to the camp and Roche throws a hissyfit because he's secretly got a deal with the Nilfgaardians.
Most of the quests that characterized the Nilfgaardians as maybe not the most enlightened people in the world, got cut. The remainders of that questline are Eye for an Eye (significantly reduced from design), Patrol Gone Missing, and Blood Ties. Coincidentally, all mine, though I don't think they were my best work; and divorced from the main quest most people never even see them.
In Eye for an Eye, the Nilfgaardians were in that village to kill the people who helped the Temerian partisans escape Velen. Which is fair in war, I suppose, though the original design was for them to be in the village capturing slaves. (I must admit, the slavery thing was not my design, and I'm glad it got removed.)
In Patrol Gone Missing there is a hidden event that probably 99% of people never see that reveals that the Nilfgaardians were executing prisoners of war.
In Blood Ties, the dwarf "coachman" for the noblewoman is actually a slave, though it's never explicitly mentioned.
The quest was pretty nilfgaard-centric and involved a renegade general (and demonologist) who was doing crazy wizard poo poo in Velen. Thaler was there, and so was Vincent Meis (but he got cut early). Iorveth was in there, trying to steal something from the demon-summoning general guy so that he could cure a plague that was killing his doods. Some parts of the old story stuck around, Eye for an Eye, Patrol Gone Missing, and... uh whatever the one is with the lady who wants you to find her redheaded kid? There was also a tiny quest in the Nilfgaard camp about some soldiers who stole a pig and tried to make it look like a monster took it. It got cut because it was bad (It was my quest, I'm allowed to say that.)
The whole nilfgaardian war stuff got cut for mostly just not fitting in well with the rest of the game and simply not having enough time to finish it properly.
Yeah, but it's super abstract. By the time we realized that Iorveth's quest wasn't working (he was actually a secondary character in a much bigger story about the war) it was way too late to add something new. About the only thing we'd have had time to do would have been to put his dead body somewhere with a note, which was suggested. I think that would have been a pretty poor conclusion to his story, so it was better to just leave him unresolved.
For an idea of what we need to do to even add a small quest. First I need to draft the quest in paper, get approval from quest lead and the director. This can actually take a couple of weeks, longer if the quest is important. Level design, environment art, character art, audio, cinematics, animation all need to get asset requests. For a small quest I'd try to avoid making more than one new character request, more than 2-3 locations. Some of the assets will go to outsource, most will be done in house.
While that's taking place (months and months of work) the quest and story teams draft the quest. This can take a while, since a lot of stuff that works on paper doesn't work in game, for many many possible reasons.
Once story is done, the text goes to localization (our writers all write in PL). From there lines are translated into a dozen languages, then sent to the studio to get actors to perform them. Those lines flow back to audio and cinematics, who put them into the game and make sure they sound right.
Meanwhile QA and quest bug-fix and iterate on the quest, basically until we ship. This includes bugs of course, but also general feedback. During this phase entire locations might be moved or redone, characters change, etc, and each team needs to respond to each change. So if QA realizes that we made a mistake and actually this character shouldn't say this or this... also he should have a red sash instead of a blue one... also his house is in a swamp and it needs to be in the forest... etc. Each of those changes means that different teams need to jump in. Textual changes are particularly nasty because it means literally hundreds of people, producers, translators, managers, actors, directors, audio technicians, cinematic artists, etc, all have to deal with it.
So I mean, in the super abstract, yes, you are right. Giving Iorveth his own side quest wouldn't have been hard. Actually, we gave him a huge quest and multiple side quests and it was even playable*. But it got cut and it wouldn't have been simple to replace it at that stage of the project.
Taken from official forum