mageykun wrote:Crystal balls are worthless, even energy- Sif, Vehumet, the staff, or sublimation of blood are better choices. I suppose if you're a shield wearing TSO worshiper you have no better choice.
Crystal balls of energy are usually worthless, but they are worth using if you have high evocations skill and know how to manage the side effects. This either means being able to resist confusion/statloss/paralysis, or just being able to cope with them. Normally sublimation is a much better choice.
Probably the most use I ever got out of a crystal ball was with an ashenzari worshipper. You don't really have the luxury of sublimating chunks if your weapon is cursed, so a crystal ball becomes a good way to get some quick MP. You'll also be immune to the confusion it can cause.
I've also used it on a caster that just had very high evocations and no easy access to corpses (sublimation isn't as good when you don't have a steady supply of chunks). I believe I used it to kill cerebov by spamming casting fire storm around 30 or 40 times without much interruption (this was back when the side effects were a lot milder, though).
I've never used a ring of regeneration- they're too rare. By the time I find them they're not worth trading an awesome randart ring for.
They're actually pretty good items. There are two ways of using them: either swap to it when you decide to rest (so you take fewer turns) or wear it all the time and have a nice healing boost (good for melee characters). My mummy wore a ring of regeneration and a ring of shaolin (+8 ev) all game, even though I had other ones available (resists etc). The reason is because resists can easily be swapped to when you need them, and they aren't needed for the majority of fights. Similarly, my current character (a hill orc) is wearing a ring of regeneration and a ring of evasion, although I'll probably replace one of them with teleport control soon.