Proposal: rigged divination.

[khalil]

The divination school of magic was removed because it was used by all builds and was generaly too powerfull. I thought of a way to solve that problem.
The first thing would be that divination spells would be innately harder to cast than other spells. The misscast chance would be higher than other spells of the same level, increased far more by heavy armor, and impossiple to reduce below 10-20.
The second would be that miscast chance is rolled twice. If you fail either time, the spell fails. Do note that this and the first can be mixed and matched as wished, as they are just there to prop up the third thing.
The third thing needed to make divination less usefull would be altered miscasts. Instead of the spell failing, it gives you faulty information.
For example, if detect monsters was cast and it failed, a room full of elder liches would show up as containing a small amount of minor undead.
Likewise, if identify failed, it would say cursed items have powerfull brands, that items with powerfull brands are cursed, and that blunt weapons of distortion have powerfull brands that don't make it impossible to butcher things.
The fourth thing would be that you can only cast a divination spell on a thing once. You can only cast identify on an item once, you can only cast magic mapping once per level, and so on. This prevents scumming where a player casts identify over and over untill they start getting consistant results, or spamming magic mapping until they get something with a vague correlation to objective reality.
Not sure if it's a good idea or not, but I figured I should get it out there.

[Sar]

http://crawl.develz.org/info/inline.php?q=ashenzari

[khalil]

http://crawl.develz.org/info/inline.php?q=ashenzari

Yes, I know you can still acess the divination spells via Ashenzari. This would make them castable spells, found in spellbooks and so on.

[Sar]

This would make them castable spells, found in spellbooks and so on.

I don't think this is desirable.

[khalil]

This would make them castable spells, found in spellbooks and so on.

I don't think this is desirable.

The reason it wasn't desireable to keep them in was because everyone used it and there were no real downsides.
I figured giving it a greater chance to explode in your face would make it unattractive to anyone who didn't want to specialize in magic.

[Sar]

Why would you use a spell if it has a fixed 20% chance to give you a completely misleading result (I assume you won't get a regular miscast prompt either)? Why would you train such a school?

[galehar]

The reason divination spells were removed if because they had an effect on a strategic level. This doesn't work because spells have a tactical cost (MP). Alter self has been removed because of the same reason, maybe others too.

[khalil]

The reason divination spells were removed if because they had an effect on a strategic level. This doesn't work because spells have a tactical cost (MP). Alter self has been removed because of the same reason, maybe others too.

I figured the real cost would be the failure results. You loose MP from casting identify and that's all fine and dandy, but the part people would care about is the chance of misidentifying a blunt weapon of distortion or whatever.
Example:
The spell tells you that what you found is a totaly legit +3 plate mail. You put it on and it turns out to be -5 cursed. Either you burn a remove curse scroll to get rid of it(thus affecting your tactical resources) or you end up in trouble during the next fight.

[galehar]

Strategic effects work much better on a god, that's why they have been moved to Ashenzari. Why would we reintroduced them as spells with special rules? We already found a solution to this problem.

[One-Eyed Jack]

There would be no real point in casting them because you would want to just equip something to verify the result anyway, or be cautious about every room anyway in case the result was wrong. Also they would be wastes of xp and spell levels anyway because you almost always get enough ?identify and ?magic mapping. Also, yeah, Ashenzari exists

[MIC132]

Also with significant failure rates, and no way to tell if the spell failed (it would be pointless to give false info if you could tell it's false info) the spells would be rather useless as the info they give would never be reliable.

EDIT: What he ^ said more or less..

[Fergy]

The reason divination spells were removed if because they had an effect on a strategic level. This doesn't work because spells have a tactical cost (MP). Alter self has been removed because of the same reason, maybe others too.

Here are my thoughts on how divination spells might be balanced. These are not necessary meant to resurrect the divination school, but could become ideas for ashenzari expansion.

Mark Target - Divination

Glow like spell that grants detect monster on the target (will work outside of LOS). Spell detects invisibillity. Spell has a very long duration that also expires if the player leaves the level.

If a monster casts this spell on a player, they will never lose track of the player (unless the player changes levels, or the spell runs out).

Balance features: Short range forces player to pay a tactical cost for a strategic bonus that may never become fruitful.

Summon Floating Eye - Divination / Summoning

Paralyzes/sleeps castor and summons a floating eye. Player assumes POV of the eye. The eye can move (fly at human speed) around the level, but cannot use any tile based feature (stairs, doors, etc). Monsters, terrain, and items appear as if using Detect FOO (but only in LOS of eye). If the eye gets hit, there is a chance of the damage being channeled back to the castor (Monsters will not follow eye, but will use spells or melee if in range. Ranged attackers will not waste ammo on the eye).

Spell power increases: Duration, EV, and LOS of the eye

The spell ends:

Duration runs out
Castor gets hit (This wakes the castor, but does not immediatly end paralysis. Channeled damage does not activate this feature)
At request of castor (There would be a Tele-like delay associated with this)
Balance features: The longer the castor spends time as an eye, the more likely it is a monster will stumble upon him. The eye taking damage is also a secondary risk.

Extispicy - Divination / Necromancy

Dissembowl a fresh corpse. Divine how many monsters of this type remain in the level.

Balance feature: Trades potential food for very limited information.

[nicolae]

Mark Target - Divination

The new sentinel's mark monster spell is similar to this effect. It might work as a Hexes spell but I'm not entirely sure how often it'd be useful. I feel like if you encounter a OOD or tough unique, you're either going to try to kill them or try to run away, and taking time to mark them would just waste time for both objectives.

Summon Floating Eye - Divination / Summoning

There's been a bunch of "caster leaves their body" spells proposed on the tavern, I don't think any of them gained much traction. What is to be gained by having to wander around physically while your body is vulnerable, just to learn information that's already mostly revealed by Ashenzari's passive mapping/monster detection? I suppose it might be useful just as a general summoning spell since giant eyeballs can paralyze.

Extispicy - Divination / Necromancy

I feel like any situation where you'd want to use this would probably be situations where the answer is probably "there's still a whole bunch".