Baldur's Gate II Game Guide

VI.7  > > > >  Mind Flayers

Invisible Stalker Strategy: (from Mishael)

  An easy way to kill Mind Flayers is to summon a bunch of Invisible
  Stalkers, then cast Haste on them.  Invisible Stalkers are immune to all
  sorts of Mind control spells including charm, domination and confusion.  As
  far as I know, they cannot be mind devoured.  You may see some marks of
  confusion on their head, but they are not confused.  You can control them
  as long as they are alive. :)

Archery Strategy: (from Jonathan Zimmerman)

  I wanted to share my battle strategy for the mind flayers in the Underdark.
  I use both pairs of boots of speed on my two best bowmen, and cast chaotic
  commands on them.  I move the rest of my party off in a corner.  The bowmen
  pop into a room with the flayers and start shooting arrows.  While the
  flayers take time using their psionics, my fighters are pumping them full
  of arrows.  Once they try to close and drain your intelligence, just back
  up and start firing again.  They will never catch you.  This works best if
  you've cleaned out the entire city, up to the first door you need a flayer
  to open.  That way, you have plenty of room to run around.  This strategy
  does use a lot of arrows, though.

  Editor's Note:  Not if you have the Tansheron's Bow (from one of the
                  Merchants in Trademeet).

Bottleneck Fighting Strategy: (from Henning Roes)

  Only one spell (chaotic command) and one fighter are involved. Cast it on
  your best melee fighter and he's protected from psionic blasts. This spell
  lasts for a long time. Then give him the best AC (-11 does it). Since Mind
  flayers have to hit your Fighter in melee they have to make a critical hit
  to drain the fighters brain. Just slaughter them while standing in the door
  so only one or two of them are able to attack. The INT-lowerance disappears
  after a short time so there's no need for a restoration-spell. Ullithids
  drain 4 or 5 levels (better than the usual Mind Flayer) - INT 5-6 is a
  must. Don't care about the Umber Hulks in the Under Dark. Use them as a
  shield while fighting and healthy. I finished the Mind Flayer City with
  only 1 spell and some healing potions. Even in the sewers in the Temple
  District it's very easy. Equip a shield to get a low AC. My fighter wasn't
  hasted or othwerwise improved.

Kill Mind Flayers with Undead: (from James Victor)

  Let someone cast Wizard's Eye and have it position itself wherever the
  mind flayers are situated.  Have your mages/clerics cast animate dead and
  let the wizard eye guide them the way.  Since animated skeletons have no
  brain, flayer's psionics are useless and since mindflayers have weak stats,
  they are easy to slaughter.  For better results, have a cleric cast
  Strength of One and another spellcaster cast Haste for better results.  A
  couple of batches of "enhanced" skeletons would do the trick.

  Editor's Note:  The Wizard's Eye doesn't do anything itself, it is simply
                  used so you can see where the skeletons are going.  This
                  way you can keep your party well away from the battle.

Mind Flayer Mind Control Collars: (from Travis Archer)

  Some SPOILERS ahead.

  These devices are one-shot mind control items which never fail.  Only 1 is
  necessary to get to the Elder brain, maybe 2 if you're unlucky.  Which
  leaves 2 or 3 extra.  These come in very handy in tough fights.  These
  devices make the most impossible combats _easy_.  The mob stays under your
  control until attacked.  It won't leave the map, but it's still your pet
  when you come back.

  I used one on the Demilich, and one on Shangalar, because:  The Demilich is
  probably the single hardest opponent because he Imprisons at will. He's
  immune to almost every spell, and he's beefy like an Adamantite Golem.
  (Weapons do 1-5 damage depending on enchantment) With one of these devices
  I made him my pet!  On a funny note, you can make him Imprison himself, but
  then you don't get his loot or experience. :( So, I used Freedom and then
  just ambushed him while he was still "green". By the time he turned red he
  was dead.

  I used this on Shangalar and he wasted his buddies while I watched, then I
  finished him off. (Wait until he gets all his defenses up before you use it
  on him)

  This can be used on Dragons as well, which is amusing as hell, but not the
  Avatar of Rillifane who is immune to everything. :(

    ToB Note:  This strategy doesn't work in ToB.