Spellcasting intervals

Lathlaer

I was wondering - since I don't really know how AD&D 2nd Ed. works - how is it that when you cast most spells, you have to wait a moment until you can cast again (hence the need for Improved Alacrity HLA) but sometimes when you cast certain specific spells (usually buffs) there is virtually no interval? What is the rule behind it?

Example? It's usually Priest combo: Bless + Armor of Faith. The second one is cast almost immediately as if under Improved Alacrity. Bless + Remove Fear. Or Heal + Armor of Faith. Or Heal + Defensive Harmony. And so on.

enqenq

You can cast one spell per round (6 seconds). So if you cast a really slow spell then you can immediately follow it with another. If you cast a fast one, say 2 seconds, then you have to wait 4 seconds before the next one.

Mitchfork

It's not really like a fixed interval "cooldown" or anything- you're just limited to one spell/ability/potion per round, or 6 seconds. Since Bless, Heal, and other spells have a casting time of a full round, you're free to cast again immediately since the next round has started. Spells like Magic Missle, Stoneskin, etc. have a casting time of 1 (1/10 of a round) so you have 9/10 of a round to wait (or move, or attack) until you can cast again. Hope this helps.

CrevsDaak

@Mitchfork you've said all what it had to be said, totally clarified, you're a genius.
And it helps a lot! Well, not to me, but I know it will help somebody.

SpaceInvader

CrevsDaak said:

@Mitchfork you've said all what it had to be said, totally clarified, you're a genius.
And it helps a lot! Well, not to me, but I know it will help somebody.

With the exception that casting Magic Missile doesn't take 1/10 round.

Mitchfork

SpaceInvader said:

CrevsDaak said:

@Mitchfork you've said all what it had to be said, totally clarified, you're a genius.
And it helps a lot! Well, not to me, but I know it will help somebody.

With the exception that casting Magic Missile doesn't take 1/10 round.

Are you sure? I was always under the impression that casting times were given in tenths of a round (thus why you never see a spell with a casting time of 10- that's just 1 round).

[Deleted User]

@Mitchfork you're correct. The casting times are all given in 'segments', a term that in AD&D and 2nd Edition used to denote tenths of a round. It's a way to balance spell casting speed against melee/ranged attacks. If you cast a spell with a cast time of 1, your cast goes off during the first segment (out of 10) that round. If you're using a big clunky two-handed sword like Lilarcor with a speed of 8, your attack doesn't happen until the 8th segment (out of 10) that round. This gets a bit more complicated when you get multiple attacks in a single round, and I honestly don't remember how that breaks down.

Spells like Magic Missile, Stoneskin, and other spells with cast times of 1 happen so quick that they look like they are instant cast. Under the effect of Improved Alacrity, they do indeed take up no time at all, which I imagine is due to engine limitations. However, it is possible to interrupt spells with single-segment casting times...you just need a fast enough weapon. That's why several backstab-friendly weapons (Kundane, Short Sword of Backstabbing, etc) have speeds of 0. If you're already autoattacking with one of these weapons at the beginning of a round and a caster tries to cast any spell, you can hit them in time to disrupt their casting.

Mitchfork

@Cyteen Ah, I suspected that speed factor on weapons worked on the same principle but I'd never been able to read anything on it. Isn't it possible for a character to be "out of sync" with another character due to how BG handles individual initiative, though? EG:

- A thief with a speed factor 0 melee weapon and 1 APR and a mage see each other, starting combat.
- The mage immediately starts casting Magic Missile (1 casting time). This sets the beginning of the mage's round.
- The thief is not within range, so as he's approaching gets hit by the Magic Missle.
- The thief gets within melee range after three seconds. The mage will be able to cast again in three seconds.
- The thief attacks, and since his weapon is speed factor 0 he attacks instantly. This sets the beginning of the thief's round.
- After three seconds, the mage is ready to cast again, and the thief will not attack again for 3 seconds. As long as the mage doesn't cast anything of speed factor 6+ he cannot be interrupted.
- Repeat ad nauseaum.

Or is my understanding of Baldur's Gate combat mechanics horribly wrong? I'm aware that in PnP your speed factor/cast time just serve as modifiers to your 1d10 individual initiative roll (so it's possible for a speed factor 8 weapon to beat a casting time 1 spell if the rolls are very lucky/unlucky) but as far as I know Baldur's Gate doesn't have any randomized initiative.

[Deleted User]

As far as I know, everybody's rounds are synched up. They're not triggered by combat - there is a constantly occurring 6 second period in which the game is resolving periodic effects (poison, True Sight, Hide in Shadows checks, etc) as well as combat actions. In your example, the thief just wasted part of the first round (in which the mage cast Magic Missile) to move towards his target. So it would probably look more like this:

Round 1
-Segment 0 - Thief and mage sight each other
-Segment 1 - Thief starts moving toward mage; mage starts casting Magic Missile
-Segment 2 - Magic Missile cast completed; thief gets hit
-Segment 4 - Thief gets to range of mage and attacks immediately due to speed factor 0
-Segments 5-10 - everybody stands around looking pretty

Round 2
-Segment 0 - mage queues up Magic Missile; thief attacks immediately due to speed factor 0. If he hits, then the cast is interrupted
-Segments 1-10 - thief snickers, mage cries

While there is no 'segment 0', I'm using it for a placeholder for 'stuff that gets resolved at the beginning of the round'. I don't know if there is any specific order for stuff like this, although I'd imagine there has to be. That's how you get things like True Sight ticking, and THEN that damn lich triggers his Mislead, causing you to waste a whole round waiting for True Sight to tick over again. :P

It can also be useful to have someone in reserve for interrupts. Think about a case where the enemy group has a cleric, who spends a few segments moving toward a target to heal. If you have your mage cast Magic Missile/whatever at the beginning of the round, the cleric gets hit but then can move and cast uninterrupted. If you watch that cleric and don't queue up the Magic Missile until they start chanting (effectively delaying your action until later in the round), you can tag them and interrupt the heal. Most of the time this isn't a big deal, but when the enemies literally have Heal, interrupting that cast can make a big difference.

SpaceInvader

Cyteen said:

@Mitchfork you're correct. The casting times are all given in 'segments', a term that in AD&D and 2nd Edition used to denote tenths of a round. It's a way to balance spell casting speed against melee/ranged attacks. If you cast a spell with a cast time of 1, your cast goes off during the first segment (out of 10) that round. If you're using a big clunky two-handed sword like Lilarcor with a speed of 8, your attack doesn't happen until the 8th segment (out of 10) that round. This gets a bit more complicated when you get multiple attacks in a single round, and I honestly don't remember how that breaks down.

Spells like Magic Missile, Stoneskin, and other spells with cast times of 1 happen so quick that they look like they are instant cast. Under the effect of Improved Alacrity, they do indeed take up no time at all, which I imagine is due to engine limitations.

Absolutely not.
The 1/10 rounds is true in the pen&paper D&D, but in game a Magic Missle takes minimum 1sec to be casted.
Also, it's definitely not instant: you can try the difference yourself by casting one with and without an Amulet of Power or a Tunic of Vecna.
Finally, even a Magic Missile with 0 casting time still isn't instant, just close.
The proof is that if you set the auto-pause after every spell casted, you won't be able to cast infinite Magic Missile.


EDIT:
Side note: a spell with 0 casting time is faster than a weap with 0 speed factor.

[Deleted User]

@SpaceInvader if it's not instant cast, it's darn close. With the Robe of Vecna, a sorcerer can cast Improved Alacrity, and dump almost their entire memorized spells before the Improved Alacrity expires (which is two rounds - oops). I can assure you that it does not take a minimum of 1 second per spell. I just tested it and dumped out over 40 spells in the duration of a single Improved Alacrity.

As for the difference between speed factor and casting time, I'd like to see some proof of this one way or the other...I'm positive I've been interrupted by melee while casting Stoneskin, which doesn't seem possible if 0 casting time is faster than 0 speed factor.

Lathlaer

Wow, those were the times...I guess that being based on battle board games didn't help TSR's D&D in simplicity

Anyway, my initial question has been anwsered, thanks guys!

SpaceInvader

Cyteen said:

@SpaceInvader if it's not instant cast, it's darn close. With the Robe of Vecna, a sorcerer can cast Improved Alacrity, and dump almost their entire memorized spells before the Improved Alacrity expires (which is two rounds - oops). I can assure you that it does not take a minimum of 1 second per spell. I just tested it and dumped out over 40 spells in the duration of a single Improved Alacrity.

As I said, it's close.
Magic Missle takes more than 1/10 round (without any casting speed boosts). Again, you can easily try it by casting Improved Alacrity and then as many MMs you can.
My bet is that you won't be able to cast 10 MM in 6 secs.

Cyteen said:

As for the difference between speed factor and casting time, I'd like to see some proof of this one way or the other...I'm positive I've been interrupted by melee while casting Stoneskin, which doesn't seem possible if 0 casting time is faster than 0 speed factor.

It simply means that the attack started a fraction of time before you clicked on Stoneskin.
To test it: put 1 mage in front of a fighter, equip the mage with a Tunic of Vecna and the fighter with a weap with speed factor 0, pause the game, cast Stonskin with the mage and attack with the fighter.

Mitchfork

I don't know how 0 casting speed works, but I remain pretty skeptical that Magic Missile (and other casting time 1 spells) take a second or longer. Half a second (or 6/10 to get technical) seems much closer to what I'm used to seeing.

Mitchfork

This is going to be a long post- and I hope this doesn't come of as "I told you so" or argumentative, but given that there is not a ton of information on how segments work in Baldur's Gate this information seemed to be worth sharing. If nothing else it required a bit of thinking to come up with a procedure.

tl;dr: Casting times are given in tenths as far as I can tell, with a small margin of error that may have a number of causes.

I loaded my save file into EEKeeper and gave my Fighter/Mage 1 Improved Alacrity and 10 Magic Missiles as memorized spells. I changed the auto-pause preferences to pause on "End of Round" and "Spell Cast."

I went to the Amaunator Statue in the Temple Ruins- this statue is an invincible NPC that doesn't turn hostile, so you can attack it freely without penalty. I removed all items that affected casting time (just the Robe of Vecna for me).

I ordered one of my Cleric/Ranger to attack the statue. In a short time the game auto-paused for Round End for the C/R. During this pause, I ordered the F/M to cast Improved Alacrity (Cast Time: 9) and unpaused.

The C/R continued to attack the statue. The F/M completed casting Improved Alacrity, and the game auto-paused for Spell Cast. I issued no new orders and unpaused. In a very short time the game auto-paused for Round End for the C/R.


During this pause, I ordered my F/M to cast Magic Missile at the statue and unpaused. The game auto-paused very quickly as Magic Missle was cast, and during the pause I queued up another Magic Missile and unpaused again. I continued to do this until 9 Magic Missiles were cast, watching the battle log. After 9 casts, the game had not yet auto-paused for a Round End for the C/R.

I ordered the F/M to cast the tenth Magic Missile and unpaused. During the casting, the game auto-paused for Round End for the C/R. The Magic Missile icon was still over the F/M portrait and she was in the casting animation. I unpaused and the Magic Missile was cast almost immediately, auto-pausing for Spell Cast.

Based on all of this: cast times seem to be given in tenths of a round, with some flakiness on the precision. This might be due to the game being very slightly late on auto-pauses, but I can't really guess at anything more than that. I was able to replicate the entire "experiment" with cast time 2 spells (1 Glitterdust, 2 Melf's, 2 Invisibilities) and the results were about the same- the fifth spell finished right after the round end.

[Deleted User]

@Mitchfork that agrees with my experience.

Btw your testing is much kinder than mine...I usually toss Magic Missiles and Acid Arrows at whoever in my party has annoyed me recently.

nano

@Cyteen It is time for more... experiments.

That explains what Irenicus was doing.

SpaceInvader

@Mitchfork Well, I knew for sure that you could not cast 10 spells with casting time of 1 before the round finished because I play (played) multiplayer pvps, occasionally.
Anyway, good job! I didn't thought you could reach 9 MM.

Alonso

Great discussion here, which clarified a lot of things for me. However, there are a few "what if" questions that have come to my mind. Rather than asking an endless series of "what if" questions, I'd like to know if there is any kind of "official" documentation about this that I can check to solve my doubts.

Apart from that, is there any mod that helps in following what is going on in a combat? While I think that I have a general understanding of combat time mechanics now, being aware of how those mechanics are applying to an actual combat (with, say, six spell casters) seems impossible.