I am pretty sure that this might have been thrown around in earlier, but here it is anyway:

Have your charge level effect every spell you cast. Have it as a special edge if it may ruin experience or something (perhaps as the end of the "held charge" you can add to "quick charge" etc).

I was very disappointed when I found out that my lighting bolt does roughly about as much damage as my +1 bolt.

So, in order to have power at the right price, why not have charge levels effect your spells?

Offensive (afromentioned lighting bolt, drain takes away more health, etc) spells have greater damage, status spells ("antigravity", "slow", etc) last longer, area-of-effect spells have even greater area of effect (with "dig" you can make several holes while "primal chaos" creates more chaos clouds), etc.

The only exception I can think of, is "detect creatures" (and consequentially, "detect walls") which cannot be raised much more (unless there is an intentional range limit, in which case lower, even remove that limit).

I think this could add a tactical aspect to the game. Planning ambushes is a bit more than just swallowing a few potions and could keep the playing field a bit more level.

EDIT:

To get the numbers behind it all, every level of charge gives 50% bonus to your effect. A level 3 charge of fireball will make 150% more damage or a 150% Haste will make it last that much longer.

I would think that the effect you get out of casting a charged spell should be proportional to the total mana that goes into it. If you charge up to 3 and cast a 1 MP spell, its effect should be tripled; if you charge up to 3 and cast a 6 MP spell, it's effect should be increased by 50%. This would keep the already strong high-leveled spells from becoming overwhelmingly powerful with just the investment of a couple of mana points.

I am not a huge fan of charge level affecting spells at all.

I think it would make it far too easy to damage spam your way through monsters. The way it stands right now the primary difference between your bolt and spells is area of effect.

The problem with using the bolt is that other enemies creep up on you while you charge and fire it at a single foe. that's good. I like that. it makes you have to consider your position at all times.

the time = damage gimmick is interesting and makes me think quite a bit while using the bolt but I don't think it would feel as unique if tacked onto everything, especially spells with much higher base effects then the bolt.

Lightning bolt doesn't do very much damage but it probably the best attack spell in the game because it is a corridor spell and it is much easier to line up enemies with it by standing in a a hallway than something like fireball. It also has an incredibly low mana cost compared to other attack spells for the number of targets it usually hits, stuns out enemies with decent frequency, and requires no time investment to reach bolt +1 levels.

Look at it this way:
(damage is based on estimated relative values)

attack damage turns targets mana
bolt 1 1 1 2
charged 2.5? 2 1 3
lightning 2.5? 2? 1 4-5 3

as you can see, six mana for two lightning bolts can kill way more guys than 2 charged bolts in half the time , with possible stunning for kiting groups of monsters and a damage type that matters in about two instances.

Just as a historical note, we tried lightning bolt at significantly higher damage in the beta, and it was far-and-away the best spell in the game, brokenly so.

As to the "charge levels benefiting spells" idea, I think it's prudent to avoid stepping on the toes of the elemental token too much. Granted, it does more than just jack up damage in most cases, but it's still a relevant comparison.

Not shutting the door on the topic at all, just adding a couple extra considerations into it; I'm very interested to hear the various views on this idea.

If the damage is to large, even considering the additional cost, there could be another way:

Give more effects to the spells.

Say, for Lighting bolt:

Charge 0 (Standard): Lighting bolt in a direction
Charge 1 : A lightning bolt is also cast on the opposite direction you aimed. For example, you cast it west, so there is a lighting bolt to the East as well.
Charge 2: The lightning bolt appears four-ways. If you cast it East, then it appears on West, North and South. If you cast it North-East, it will be cast North-West, South-East and South-West as well.
Charge 3: Lightning bolt is cast in all 8 directions, plus in immediate area.

In other cases, like Detect Creatures/Walls the spell's effects change.

Say, Detect Creature

Charge 0: Detect nearby creatures
Charge 1: Detect nearby creatures for a few turns.
Charge 2: Detect nearby creatures and wells for a few turns.
Charge 3: Detect nearby creatures, wells and items for a few turns.

It's opposite, Detect Walls

Charge 0: Detect walls.
Charge 1: Detect walls and doors.
Charge 2: Detect walls, doors and special tiles (lava, acid, holes, etc).
Charge 3: Detect walls, doors, special tiles and stairways.

In other cases, effect is greater.

BTW, Nahjor? Could you add a display to flags for how many turns/charges does it last?

Actually, I'd be more in favor of adding damage for charges than I would be for adding additional effects; I dig the fact that the elemental token provides a benefit that's impossible to obtain any other way. (Which leads to a tangential point that not every spell has the best, or any, interaction with the elemental token- that's going to get addressed for the next big version too.)

Let's say I added an edge that allowed you to add damage to spells while casting them with charges; 1 pt per charge level. The charges would be consumed, just as with a staff bolt. Would that be a sufficient balance, given that it requires you to spend an edge? Would the edge need prereqs? Should the edge be able to be taken multiple times?

I was definitely expanding on your idea and digging for specifics of implementation, not obviating it.

Specifically, there's a big difference between what I noted there, and in how charges effect your bolts right now. A single charge adds something on the order of 3 damage to a bolt, not the 1 damage that I mentioned as a possibility for how much it could add to spells.

The reason I suggested that this only apply to damage is because, again, this keeps the effect of the elemental token unique.

Elemental tokens are rare and far between. Besides, it overcharges spells without you yourself needing to charge.