[Faceman]

If you really want to use the Staff of Cheese a.k.a. Staff of the Magi do the following (preferably with a Fighter/Mage/Thief): (this works on any enemy that cannot naturally see through invis like KuaToas can)
1. whack the Beholder
2. reequip the staff
repeat until Beholder is dead.
Every time you reequip the staff you go invis again and so you won't get hit.
As for the Flayers: Remember that they are physically weak. So if you can't resist their psionics go for melee. A good (i.e. well equipped) tank will not take more than 3-4 hits to kill a Flayer while missile damage (though great if you manage to avoid the dominations and stuns) will be too weak to kill them before they suck the brains of a stunned party member. For single Flayers or as a starter backstab them. A solid backstab should be sufficient to kill a Flayer or at least get him "yellow".

[ 10-01-2003, 05:59 PM: Message edited by: Faceman ]