So, most places on the internet seem to assume that when one plays Baldur's Gate one plays it fairly heavily modded. Personally, I'm thinking I want to make a run at it with a pure vanilla version. Why? A few reasons:

1) I've never beaten either game (and really haven't gotten far in either). I'd kind of like to experience just "the game" before digging around in its guts.

2) I have actually tried to play BG1 with the EasyTutu mod, but the Beregost bug stressed me out. I'd rather not have to worry about something like that unless I'm just screwing around or something.

3) The "retroness" of a title doesn't really bother me much. If I like a game then I'll like a game (and if I don't, I won't). I don't need to try to pretty it up to enjoy it.

But, as stated before, everyone always assumes both games are heavily modded. Is it really that horrible playing vanilla, or what?

caveat: I've not played vanilla myself

I just finished my first playthrough and used Baldur's Gate Trilogy mod to play it (BG1+2) as one big game. That's about the only game-changing mod I took (added a couple of minor convenience tweaks and, of course, the fix-pack).
It just gives the game the BG2 UI and the better path-finding (though also makes the spells and items consistent with BG2).

I'm about to play through a 2nd time and try a few more mods out (NPC banter-pack / one or 2 quest mods, maybe 'unfinished business') but I didn't feel the original missed anything.

I know some people who think the vanilla BG1 plays just fine as is (and I don't think any content need be added for a 1st playthrough, especially if you're playing 'good')

No doubt those who've played a few times will have more reliable advice ;)

I used to have the same thoughts about BG1. I hadn't completed it yet, so I wanted my first playthrough to be without mods, with the exeption of the widescreen mod, like the game devs intended. Over the years (I bought the 4 in 1 box set probably in 2002) I started playing the game from the beginning several times and never finished it. At some point I always realized I hated the mob spawning and lost interest. Or maybe my character was boring.

I'm currently playing BG1 with EasyTutu and enjoying it more than ever. There's a fix for the Beregost issue on the EasyTutu web site, as well a tweak for the mob spawning, which made it for me. I really can't see any significant differences to the unmodded version I used to play, that I would rather play unmodded first.

I'm past the first half of the main guest, so there still could be something coming, that I don't like. And many unexplored areas for side quests. But as I said, so far this is my most enjoyable BG1 game so far.

Edit: I also use the Unfinished Business pack.

Playing vanilla is the normal way to play the game and most players did and still do so.

But Baldur's Gate is just so bland, boring and mediocre without Sword Coast Stratagems and the BG1 NPC Project...
BG 2 OTOH is still a cracking good game in its vanilla state.

I disagree. I definitely miss the party banter in vanilla BG1, but stand along I think it is still a great game. The only issues I really had with BG1 vanilla is that it looks really bad on a modern monitor and the level cap (I remember capping out with still about a quarter of the game to go). The widescreen mod and the level cap remover fix those quite easily though and the game is still 90% vanilla.

I have finished baldurs gate 1 three times now and allways without any mods , i was looking around for the party banter mod but seems i need tutu , or weidu or those kind of mods because i could not install it , perhaps is that i was doin it wrong , but it was self installing so i dont think so :P anyways my point is that even tough i wanted to try that mod it has not being so much on my mind to try tutu and such , i dont even use the widescreen mod because ive read that you see a lot more of the area and thus some parts that are suposed to be ambush dont work like it since you can see them from further , still ive not tried the mod myself so not sure if thats true , i defenetly would recomend allways play a game without mods for the first time , if you hate the resolution of the vanilla game then i guess better to use widescreen mod then not to play at all , eather i am to chilled about things , or people just like to complain way to much , because i dont see any problems with the vanilla game , its your choice in the end tough and i hope you enjoy baldurs gate as much as i have :)

What's this game have to do with vanilla?

Vanilla is a term used for when a game is just as it was made , without any mods ,tweecks and things like that , i was not sure what it meant the first time i heard it eather :P

I played through the vanilla game a couple of times, but after playing with Tutu & BG1 NPC's I would never go back.

There is a writeup I found comparing vanilla to Tutu
[url=http://www.playithardcore.com/pihwiki/index.php?title=Baldur's_Gate:_BG1TuTu_vs_Vanilla_BG]http://www.playithardcore.com/pihwiki/index.php?title=Baldur's_Gate:_BG1TuTu_vs_Vanilla_BG[/url]

You get a better engine with improved UI and capabilities, and enemies have improved AI.
This makes things sometimes easier (new abilities) and sometimes harder (improved enemy AI means it is not as easy to kill via exploits)

I've played Tutu (as part of BGT) recently and were annoyed by many things (it's not just an engine update), I recommend playing vanilla, Tutu is for spoiled replayers who want to try something different.

I'd play it with Tutu just for the better NPC movement in the mazes here and there. It's down right infuriating to have them windowlickers run off in a different reaction just because it's narrow and they happen to bump into each other. This still happens with Tutu on max nodes, but it's not quite as bad.

Also found vanilla annoying because you can't see any items or which chests etc can be opened with the Tab key (or whichever it was). That may seem like a small thing, but it can be quite frustrating at some points where you are to pick up a ring or whatever from the landscape.

It's not a vastly different game with Tutu of course (unless you use all kinds of cheats in some of the mods), but some of the changes make it a better gaming experience IMO.

Most BG players seem to overwhelmingly play with mods loike TuTu/BGT. The first time I beat BG I did so playing vanilla, and it was a good time. But TuTu just makes the game better. As if the developers were able to go back in time with their BG2 engine and re-write the game with less technical problems, a better implementation of the AD&D rules and several other improvements.
It is not like you are playing a really 'modded' game at all(more like a patched(for bugs) game).