Do a search on mindflayers in this forum and you'll get all the answers you need. But since I'm in an indulgent mood today I'll summarise it for you [img]tongue.gif[/img]
Summoning skeletons is very useful because even though they cannot really harm the mindflayers, they are immune to their psionic attacks (doh, they have no brains!
) so they serve as a nice barrier between your party and the illithid. You can summon skeletons with the 5th level Wizard spell Animate Dead or the 3rd level priest spell of the same name. The fifth level priest spell Chaotic Commands also protects you against most of the illithid's psionic attacks.
Don't use magic on them unless you cast Lower Resistance first, because they have high Magic Resistance.
If it still doesn't work, here's a good cheesy tactic only works when mindflaers are in closed room:
- make your mage (improved) invisible and non-detected, and equip him/her with a WAND of Cloudkill (so the wand, not the spell). Have the rest of your party stand well back, and have the mage open the door to the room where the illithid are. Cast Cloudkill in the middle of them and quickly close the door. Repeat until the mindflayers are sufficiently weakened, then send the whole party in to finish them off...