If some of my characters flee a battle, does their share of the experience get lost, or does it go to those who don't flee?

The reason I am asking is because of this potential strategy for leveling up a specific character:

1. Kill all but one enemy.
2. Disable that last enemy.
3. Have all but one character run away.
4. Have the last character kill the remaining enemy.

Will this work for giving one specific character tons of experience? (For example, to speed up getting a dual-class character to regain her abilities.)

My God, just play the fucking games already!
They are not that difficult that you need to resort to such tactics.

I don't yet have the games.

Also, sometimes when playing these sort of games, I might like to introduce a new character mid-game, and wondering if such a method would work for leveling up a new character.

(I actually did use this sort of strategy in Elminage Gothic, but then again, that game does get rather difficult later on.)

At the end of battle, experience for killed monsters is divided only among those character that are still left standing, i.e. who did not get knocked out and did not flee the battle.

Also, you don't have to keep one opponent alive. All Goldbox games ask you whether or not to continue battle at the end of the round in which the last opponent has been killed (except the Eye of the Beholder games, for obvious reasons); simply answer with "yes", then flee with all the characters you want, and continue answering "yes" at the end of each round until only those characters are left that you want to earn XP. This has nothing to do with the game being too hard. It's the design of the games themselves that make such tactics viable for a couple of reasons.

First of all, some classes need way more XP to reach a new level than others -- just compare thieves and mages. This also means that some classes may hit a game's level cap long before others do (single-class clerics in Pool of Radiance are prone to this since they can only reach 6th level, and clerics don't need that much XP).

And secondly, multi-class character take way longer to level up, especially triple-class characters like cleric/fighter/magic-user, or fighter/magic-user/thief. Fleeing with all other characters at the end of the battle is a simple way to boost the XP of such slow-leveling characters, and it's absolutely viable to do so even though it's not really necessary.

I'd say the best place to use this is probably in Secret of the Silver Blades, to ensure that your dual classers catch up (or are ready to catch up at the start of Pools of Darkness), since it's a common strategy to want to dual your warrior types over to casters at level 13 (or 15 for rangers) so that you can have that dual attack per round once the original class resumes. Secret not only provides motivation to focus that much XP onto single characters if that's your thing, but also provides the best opportunity to do so (especially in the late game where a really common random encounter is with 10-15 human warriors and mages, of which all the warriors have +2/+3 gear and the mages have bracers of at least AC4, and there are also the cloud giants with their giant sacks of cash in the same area).

The big thing is that in order for your stratagem to really be useful, in addition to the desire to stack XP onto less than the full party, you need to have a suitable encounter to milk. Non repeatable story battles don't really work so well for this because of their one time nature, which means you need a random encounter that gives lots of XP and which preferably isn't numerically capped. Unfortunately, the Gold Box games mostly don't really quite oblige that well: the system is heavily biased towards giving most of your XP from treasure rather than kills; as a result, even high tier monsters tend to pay out very poorly in terms of XP unless they also drop fairly substantial loot (which pretty much means they have to drop Jewelry, thousands of coins, and/or magical equipment).

This pretty much means encounters of one of two sorts:
* Humans/humanoids sporting higher order magical equipment (and preferably not Drow because "Drow" items are worth very little)
* Giants, who almost always carry several thousand coins per encounter.

Apart from Secret, sadly, the only game that really fits the bill well is Pool of Radiance (with the giant encounters in the castle late game, in particular), and even that's of fairly little usefulness (mainly because the characters you actually want to import to Curse are going to be the ones who hit the level cap long ago - yeah, namely those mages and clerics; the level limits make most multiclass characters more or less dead weight after Pool, and importing fighters to Curse is buggy and usually results in needing to hex edit characters).

One would love to use it in Treasures - especially since multiple dualed Mages are almost a must for getting through the endgame without tears - but finding good encounters to grind is difficult (Giants exist, but I'm having a hard time remembering if there are any good "hotspots" where you can easily get repeated fights; most of the fights with magic wielding humans are fixed rather than random, plus have the whole "enemy reinforcements" thing that makes drawing out the fight problematic, I can't remember if reinforcements will show if you extend the fight for additional rounds once the current enemies are dead but before all scheduled backup has arrived).

Curse and Gateway just don't have the random encounters you need (I think there is one spot with giants on one of the islands but its distance from civilisation, and thus training, is a problem). Pools of Darkness may have some OK fights but not as good as Secret (the humans don't tend to carry as powerful magic items as the ones in Secret did, in particular; most of the enemies with good magic gear are Drow and that gear doesn't have the same impact on your XP as "proper" magical loot).

Arguably 'failure to oblige' is good game design. ;) But your mileage may vary on that one.

Gold Box level grinding:

Pool: The castle, as you've suggested--set off the alarm and then move in Search mode--you'll only have a few encounters before the alarm ends (it only lasts an hour).

Often overlooked is starting fights with the town or council guards. They have lots of equipment--Javelins of Lightning, Plate Mail +2, Rings of Protection +3, and so on. The problem is you won't be able to use shops or temples until you complete a mission. (BTW, the temple of Ilmater in Podol Plaza will never find out you attacked the guards, so you can heal and ID items there.) So complete a mission, battle your guards, and then go in and get your reward from the clerk and then the shops and temples will talk to you again.

Curse: There are numerous dungeons scattered around the various cities once you've eliminated one of the bonds after Tilverton which are basically just there to let you level-grind. You can always search to find an exit.

Secret: Not sure--I just ran through it as quick as I could; but there are quite a few not-so-hard monster encounters in the mines which have random magic items to loot.

Pools: The two biggest areas to grind are both extradimensional: the random encounters in the mini adventures in the Web Dimension, and Moander's Heart in Moander. The Heart clears out after you beat Tanetal, unfortunately.

Could you elaborate? I don't mind having to hex edit because I expect to be hex editing female characters' Strength so they can be as strong as male characters, but I would like to know what to expect. (I am also curious if the bug is exploitable in some odd way.)

The bug occurs whenever you import a character into Curse that had exceptional Strength in Pool, and post importation that character is subjected to any magic that alters Strength (whether gear, spell, or potion). At this point instead of the expected functionality the character's Strength is promptly overwritten by their former Exceptional Strength value, and it will not revert to the correct value normally even if the effect in question is removed; the only way to restore the character's ability scores to what they should be is to hex edit the character's file.

Characters without exceptional Strength do not suffer from the glitch, so non-Fighters import without issue. The bug also does not trigger if you don't use any Strength altering magics on susceptible characters, but I do not know if the bug persists past Curse (i.e., if you take a character vulnerable to the glitch through Curse without using any Strength enhancing gear or items, then import them into Secret and try to use same there).

I'm presuming there is exploit potential if you import a character whose Strength is in the range 18(19) through 18(25), but it's probably not really worth it (that means you have to go through Pool - where the bonuses from high Strength probably help the most - with lower Strength to get the higher score in the later games, and there's enough Str enhancing goodies later on the series anyhow: the Girdle from Curse is a semi permanent 24 due to another import glitch in Secret, Secret and Pools themselves have multiple 23 Strength Girdles, and Enlarge jumps it to 22 anyway and has a decently long duration at those levels and it's not like enemies use Dispel Magic with any regularity).