Anyway, here's how it'll work:
Your average 5.5-feet-in-diameter beholder has 10 eyestalks:
- Charm Person
- Charm Monster
- Sleep
- Telekinesis
- Flesh to Stone
- Disintegrate
- Fear
- Slow
- Cause Serious Wounds
- Death
Each round the beholder is able to use a randomly selected subset (roughly 5-6) of these eyestalks.
Most of the rays function like the corresponding spells, except they all only affect a single target. This includes the anti-magic ray, which will dispel all spells affecting the target and prevent any other magic from affecting him or her (including the beholder's own rays). Beholders will use their disintegrating eye by default, but if perma-death isn't your cup of tea you'll have the option of turning it off (i.e the reverse of SCSII's turn-disintegration-on scheme).
The beholder can take 50 points of damage before dying. However, the central eye and the eyestalks have their own HP and you have a (random) chance of hitting these instead. Disabled eyes still count as one of the 11 eyes, so if the beholder's unlucky one or more of the eyes he can use that round will be disabled and useless.