For one, the silence effect should be scaled more strongly with caster “power”; possible inputs are:

• spell power (already bound to duration as it's a self-enchantment)
• level of air skill

Then the question of how the effect itself can be scaled:

• Range.
• Strength – give each cell in radius a silence level, and check monsters trying to cast against that.
• Duration.

It would be nice to combine these: Silence effect decreases with distance, and the shape of the decrease depends on the power of the effect. Silence could be made to decay as it nears the end, similar to the way the sanctuary times out.

• Flat check of monster HD against silence strength.
• Randomized check of monster HD against silence strength; monsters could try, but would have a chance of failing (and losing a turn?)
• Just fail to cast, or a chance of miscasting? (utter failure for silence » caster power, miscast for silence > power, success else)

I like the idea of Silence fading inwards, so that it places the PC in jeopardy towards the end of duration. I do think someone pointed out about this mechanic, that this can lead to (more) tedious hit-and-run back-and-forth playing. OTOH.. if you run away from the casters, they get a chance to cast from distance anyway, so with dangerous casters it's not 100% safe, might be ok I'm thinking.

As dpeg pointed out on IRC, removal (of spell, keeping scroll?) is an option. — evktalo 2009-11-24 07:46

Idea by purge: replace Silence by an effect which may cause everyone to miscast.

I second the fading Silence. Once that's in, the same should apply to the scroll. Perhaps with the difference that the spell centers on the player whereas the scroll's center is fixed (the place where it was read)? That would make it trivial against stationary monsters, of course… Not trivial vs liches etc., though.

By the way, clever monsters (liched, pan lords etc.) should be able to leave the silence range.

Finally, if the Silence changes are in, we should make curse skulls respect silence again, I think. — dpeg 2009-11-24 08:20

Making scroll's silence effect stationary makes me think it should be a future misc item single-use effect. Nice to be reminded about them! — evktalo 2009-11-24 09:59

Eronarn suggested, on IRC, an asphyxiation-based silence effect. (I think this could be an erratic cloud as well!) It wouldn't work on undead, but it could suppress breath weapons as well! — evktalo 2009-11-24 10:01

Silence is already described as making nearby monsters suspicious. What if it had such an effect throughout the level, making enemies within around 20 squares start to wake up, and awake monsters within 40 or so squares know your position and come to get you? This would magnify the natural risks of silence, a hybrid being caught by tough enemies without her normal bag of magical tricks.

Of course, the best way to model this would be to make silence, well, noisy. — nrook 2009-12-19 06:47

What's with all these HD checks ? Are you trying to say Magic Resistance - which should fill this role - is Fucked Up Beyond All Repair ? — b0rsuk 2009-12-19 07:17