Oh, finally a use for that 'Know Allignment' spell... :)

Actually, it would be a pretty cool feature if monsters were sometimes generated with different alignments.
Imagine if the chances of an orc being C/N/L are 90%/9%/1%.
For one thing, it could explain why you occasionally meet a neutral or friendly orc.
For another, if you break open an orc room and live-sacrifice everyone inside on an altar, you could get unlucky and anger your god! It adds an element of risk to live sacrifices, which is currently very easy (maybe too easy).
And yes, it would give a use for the Know Alignment spell.
So if this is a bug, I request it not be fixed--but retained and even possibly extended. Probably some monsters (demons and unicorns) should never deviate from their base alignment, but the nonmagical ones should be able to.

I don't know if it related, but i was just sacrificed by hobgoblin (which i'm pretty sure should be chaotic) on neutral altar while i was lawful.

Yep, that's exactly the problem here. All hostile monsters seem to have their alignment as neutral...

I'll second that. Yeah, some monsters are meant to be inheritly good, evil or neutral but some might be able have variable alignment just like PC can do. It feel unusual, but... Why not?

The problem here is what happens when you walk over an altar like AltarAsc did, and a random monster that is normally not that alignment sacrifices you. A lot of people would probably get pissed off about it, so I don't think that would be a real fun thing to have.

Although it would give a use for the "Know Alignment spell", it might not be the worth the pain.

Actually, I think it would only be a problem until players learn of that change, get used to it, and after that point it would merely demand more caution when dealing with altars. People would still have many options at their disposal: replicating the same tactics used with chaotic altars, finding out the alignment of the present monsters in some way (spells, abilities etc.) and so on.

Though if this were to really be a feature, it might be a good idea to increase the ways in which one can find out a monster's alignment. That could include wands, scrolls, possibly a spell/scroll/wand that would reveal the alignment of ALL monsters nearby. Alignment could also affect the monster's AI in some fashion. Not in any supremely obvious way that you could always tell it at a glance, but it could react differently to certain situations and interactions. This last one isn't fleshed out at all yet, but it could possibly be the most interesting. It might work in a way that if you observed a monster's behavior for a while, you could probably find out its alignment, but the spells/stuff would still be more effective should you have access to them in that they work instantly and will tell you the alignment with 100% certainty. (These AI changes could include anything basic like different attack tactics, whether certain actions anger them or not, or more obscure ones like, say, if you drop an item on the floor, and there is a non-hostile lawful and intelligent monster nearby, it might feel inclined to pick it up and hand it to you, saying you dropped it.)

As a matter of fact, this is starting to look like a feature request, I might just post it there too. Do tell me what you think of it if you'd like to though.

All monsters turning neutral after becoming hostile definitely sounds like a bug, not a feature. Also, having to check a monster's alignment constantly when trying to make live sacrifices on an altar doesn't sound like it would add anything positive to the game... rather, more tedium.

Agreed. The game is tedious enough as is. There are plenty of ways to make the gameplay more interesting and unique, but this is definitively not one of them.

Oh no, you misunderstand me. The current situation as described is obviously weird and seems to be a bug, it's just that the discussion has wandered into a related topic, about monster alignment variance. Because let's face it, right now, monster alignment is a redundant variable since a monster's type determines it, and that also makes some related gameplay elements (like Know Alignment and a paladin class power) almost entirely useless. The question is, how best (if at all) to introduce game systems that would transform monster alignment and related spells into something more meaningful beyond just categorizing monsters, but not providing any useful information other than what is already seen instantly by looking at them.

Also, as I said, introducing some randomness to monster alignment would clearly only work together with adding new ways to find it out, hell, possibly even ways to change it.

Fixed. This was introduced by some of the adjustments for the "pampered" game mode :-(