I noticed Minsc has been confused and dire charmed at times while raged. Just wondering if it does anything besides the hp bonus. (Baldur's Gate 1: original edition)

No. In original BG1 all that Minsc's Berserk does is make him unpredictable in exchange for a temporary 15 HP. Unlike BG2 it does not make him immune to Charm, Sleep, Confusion etc.

Thanks.

There is one side effect that the rage has, at least in Baldur's Gate 2/TuTu (but probably in 1).

When the rage ends, it does 15 *damage* to Minsc. This has the following effects:
1. If Minsc is casting a spell, the spell will be disrupted. Similarly, if Minsk casts Project Image while the rage is in effect (impossible for Minsc without glitches or mods, but possible in BG2 for a dual Berserker/Mage), the effect will end when the rage does.
2. The damage is affected by difficulty. If you are playing below Core Rules, this ability will give you a bit of net healing (though your HP will still be limited by its normal maximum). If you are playing above Core Rules, however, you will end up taking *more* than 15 damage when it wears off. This means that if Minsc's maximum HP is 15 or less and he rages, he is not going to survive unless you cast something like Aid on him.
3. The damage might have a type (probably Energy, I'm guessing). If you are able to resist that type of damage, you can avoid some or all of the damage, or even turn it into a small amount of healing (if you can get the resist over 100). This can be used to mitigate point 2, but not point 1.

Haha, interesting. I just wanted to know because sirines are annoying. Because of the lack of charm protection in BG1, my strategy at the moment is just to send someone alone to fight them and damage them in between charms.

No it doesn't. It's deferred raw damage set and applied by the Berserk innate ability.

Most of your points are moot in BG1 original. What's interesting is that there is a Helmet of Charm Protection in the BG1 files, but it can't be found in-game. Shame that.

The reason I guessed the damage has a type involves a certain ability in Baldur's Gate 2. That ability will do energy damage to you a few times before it kills you outright, and you can block the energy damage (or even turn it into healing) with energy resistance. (That doesn't prevent you from dying later, however.) If you cheat to get that helmet, does it actually work properly? Some games have dummied items that don't work properly (or have bugs), while others have dummied items that do. The second Dark Sun cRPG (Wake of the Ravager) even has 8th and 9th level spells accessible through cheats, with varying levels of functionality. (Meteor Swarm appears to actually be pretty good in that game, while Prismatic Sphere crashes the game.)

I don't use cheats myself, so I really have no idea if it works in practice. It's ability, however, is simply immunity to 'Charm Creature', and since (as far as I remember) that works in-game there's no reason to believe the helmet wouldn't work.

Have you used a "Scout" like Imoen Shadowed to spot the Sirine. Have your other players just outside the Sirine's vision, then attack with missiles from all. You'll have a good chance at disrupting their spells. (Make sure your players have some distance from one another in case it doesn't work and one gets charmed.)

Yeah I tried that a few times, it seems like sometimes they will take damage while casting, but will still finish casting. Other times they are interrupted, so I don't depend on that strategy too much. Not sure the exact mechanics regarding spell interruption or if it's a percent chance. It seems like it's a 100% chance for me when I get hit while casting. Sometimes I do scout though, and then cast wand of sleep from outside the sirine's vision.

I believe it works something like this:

If a spell is cast normally from memory (if from a script, via CastSpell()), the spell can be disrupted normally.

If an item (such as a scroll) is used to cast a spell, the spell can't be disrupted.

If the spell is cast via ForceSpell(), the spell can't be disrupted. Unfortunately, many enemies in the game do in fact cast spells this way, even though it could be considered cheating. (I believe some mods that are intended to make the game harder actually try to avoid this, but the vanilla game has enemies cheating this way.)

Darn cheaters! Minsc will not stand for this!

Go for the eyes Boo, and those cheating typing fingers too!! >:)

I guess you will need to make your own AI script that has your characters cheating with ForceSpell() or even ReallyForceSpell(). Maybe have Minsc ReallyForceSpell() Improved Invisibility on himself every time it wears off. (I think this sort of thing is more fun than just using the cheat console.)

The distinction is something like this:
CastSpell(): Spell will be cast if memorized, will be removed from memory, can be disrupted. The usual 6 second rule applies.
ForceSpell(): Spell will be cast even if not memorized, but I believe will be removed from memory if it is. Can't be disrupted. I *think* the usual 6 second rule applies.
ReallyForceSpell(): Spell will be cast instantly, ignoring the usual constraints. The 6 second rule does not apply. This is used in cutscenes, and some enemies in BG2 will ReallyForceSpell() spells under certain circumstances, often accompanied by text like "Contingency" and "Spell Trigger". (The AI can't actually cast these spells, so the developers faked it with AI scripts.)