I've played this series (well 1-4, I couldn't ever get into 5 even as a kid) a billion times, but realized I've always played it through as a pure class. I find the thief to be my favorite, and I've mostly played the series that way, as I enjoy the whole breaking and entering and thieves' guild aspects.

If I make a mage, and pick up some thief skills like lock picking and stealth, can I still get access to the thieves' guilds in 1-4? I've read that in some cases, what you can/can't do is dictated by the base class rather than just simply having put points into another class's skills. Or would I have to start as a thief and put points into magic?

I guess what it boils down to is that I'm curious if by starting as a mage but picking up stealth/lock pick, will I be able to experience all the mage specific quests throughout the series, but have the side benefit of being able to fence my loot at the thieves' guild? That's really what it boils down to.

I know it's not possible with a hybrid to have access to both class's specific quests, I'm just specifically inquiring if I can get into the thieves' guilds throughout 1-4 as a mage assuming I pick up thief-specific skills.

Thanks!

Edit: Just tested in QFG1 starting as a mage and assigning points to stealth/lock pick and it let me in. I'm just not sure if this is something I'll be able to keep doing when I import my character into 2,3 and 4.
Edit 2: Seems to be no issues in doing a bunch of thief stuff in 2. Upon importing my character from 1 I had a lock pick, thieves' toolkit, and the thieves' guild license. I'm going to assume that there are no issues with the latter games either.

This series supports what is called a mixed character or hybrid - see https://questforglory.fandom.com/wiki/Mixed_Character.

While in QFG1 all tasks were open to everyone depending purely based on their abilities and skills, with each game more tasks became pure class specific.

For the full list of which tasks are class specific, see https://questforglory.fandom.com/wiki/Class_Quests.

>>Yup, although only the first and the fifth games have a thieves' guild.

Actually, there IS a thieves' guild in QFG4...sort of.

Spoilers...

Under the adventurers' guild, there is a secret passage that leads to the MOSTLY abandoned thieves' guild. I think you may have to be a thief to access it, though. (It's been a long time since I played QFG4.)

Nope, please read the aforementioned wiki to see the only quests which require a class.
Any mixed character can enter this guild.

Also, QFG2 had operations that were closed to a guild and QFG3 had rumors of one - see https://questforglory.fandom.com/wiki/Thieves%27_Guild.

To be honest, even though 5 is in some ways my favourite game in the series (even if Erana is quite off-model: she never had a consistent appearance though XD) I absolutely despise the Dancing Man lockpicking minigame with twelve burning passions. It's enough to make me never do a Thief run, hell, even a run where I have Pick Locks. Fighter to Paladin with hybrid points in everything except Pick Locks remains my favourite build. I guess it's fitting because I like the fighting in 5, as clunky as it can be. IMO, Fighter has the best combat/puzzle ratio in the series, and plays like how Adventure RPGs should. Stat blocks should be more than just a way to mess up puzzles without having to reload, and more than just stat checks to succeed at puzzle actions. Robust combat systems and at least a few mandatory fights are a must to get the best of both genres.

But yeah, hybrids can't do everything. It's a nitpick of mine in fact - it would be quite nice for my Paladin to also be able to do all of the Wizard content. Complete the Simbani initiation and then have to magic duel the Leopardman shaman to get the Spear of Death? Yes please. Even something as simple as being able to do the elf battle in 4 as a Paladin could have had a hybrid-exclusive interaction where Devon sniffs out Tatiana's trap with danger sense- and catches her off-guard, letting you enter the fight with your buffs up already. Heroine's Quest understandably (from a balance perspective if not a rule of cool one) nerfed mage hybrids hard, but that game feels like it only has hybrid options at all because QfG did. It really doesn't like hybrids all that much. Personally I would have tied Parry into being a fighter hybrid stat that let you use more weapons like QfG1 planned to do.

Yes, this is a three decade old series, but it's a genre maker with untapped potential, and anyone who wants to try to tap that potential can take notes. Hell, take some of mine!