[Technique]

Originally Posted by Byrjun [You must be logged in to view images. Log in or Register.]

Yeah, from 2003. This was a mechanic added in mid-to-late Velious so that they could start making encounters that were unslowable, but wizards could still nuke or whatever.

I didn't mean to imply that it wasn't added in Velious.

October 8, 2001

Magic System Changes

• The level-based spell resistance bonus inherent in super-high level NPCs has been reduced significantly.
• Several NPCs have had their resistances reduced. Each of them was examined carefully, and resistances changed as seemed appropriate. For some of these NPCs other things were changed as well to compensate for their increased susceptibility to spells, such as armor improvements or perhaps greater hit points, if needed for that NPC.
• NPCs that were highly magic resistant in order to make them immune to certain spells can now be given specific immunity to those spells. This means that they can be made immune to critical spells, as intended, and still be generally less resistant to magic. Players will receive a message similar to the one that is already given for Mesmerization spells when they cast a spell on an NPC that it is specifically immune to.

IMPORTANT NOTE: It is very important to note that we have not made any NPCs immune to spells that they were not already immune to. Many NPCs that were previously immune to spells due to their high innate resistance to magic have had that resistance reduced and specific immunities added. So if you see an immunity message after attempting to cast a spell on an NPC that you hadn't seen such a message from before, understand that the NPC was already immune to that spell before due to high resistances, and the only difference is that it now has lower resistances in general and specific spell immunity (which is why you are seeing the message).

http://www.tski.co.jp/baldio/patch/20011008.html

From the Developer's Corner post mentioned in the patch notes:

we’ve given our designers more control over the ability to customize any particular encounter. For example previously, if a designer didn’t want a creature to be mesmerisable, he had to give it high magic resistance. Now they can set that feature individually while keeping magic resists reasonable so they don’t take a bunch of classes out of the picture through the need for one feature.

Players will now also receive messages when an NPC is immune to a particular type of spell, much like messages regarding mesmerization have always been sent. We can do this since the designers have direct control over the effectiveness of certain utility effects, while still allowing damage-causing spells to go through. As an example, NPCs that were always immune to melee-speed debuffs by virtue of the fact that they had a very high magic resistance will still be immune to those spells, but magic-based spells that cause damage or do some other effect that the designer didn’t necessarily want to rule out would now go through.
Finally, to compensate for increased magical damage, some NPCs have received additional abilities and/or stats. This serves to keep the encounters at a similar level of difficulty while balancing the contribution of melee and casters, rather than engaging exclusively in the melee-heavy strategy of before.