Why do so many enchantment spells have HD limits?

[Ellington]

Daze, hypnotism, sleep, daze monster, deep slumber, lesser geas, bungle. All of these enchantment spells have a fixed HD limit that never increases. So do Cause Fear and Scare, necromancy spells which affect the mind. I realize these spells have powerful effects, such as sleep, which can singlehandedly beat encounters at lower levels, but they quickly become completely useless and make you regret picking them in the first place.

Why is this? You don't see powerful conjuration spells such as grease, create pit or black tentacles only affecting creatures of a set HD. Your fireball never fails to damage a creature because its HD is too high. Why is enchantment treated differently? It's not the strongest school and has got plenty of problems, I don't see the need for a handicap like this.

At least allow the HD limit to scale as you gain levels.

[Josh M Foster]

I see it as being similar to the dice cap in fireball or burning hands. Since these effects either happen or don't (unlike varied damage of a lightning bolt, etc), though, the best way to cause obsolescence wasn't to limit damage (of which there is none), but the power of creatures affected. Person/Monster distinctions are similar. Some, though, just work off HD

Perhaps allow a metamagic feat similar to intensify that ups the HD limit, then?

[Mojorat]

ALOT of conjuration spells are basically environmental effects. so you cast a pit on the ground the bad guys either walk into it or they don't you do not cast it at them. some conjuration spells like cloudkill do have limits though..

[Kalyth]

Mojorat wrote:

ALOT of conjuration spells are basically environmental effects. so you cast a pit on the ground the bad guys either walk into it or they don't you do not cast it at them. some conjuration spells like cloudkill do have limits though..

I would much prefer if these spells had a lesser effect on creatures of higher HD but still some effect. Daze could instead stagger if the target was above the HD limit. Sleep could fatigue a creature of greater than 4 hd, etc.... I just hate how the spell becomes completely useless. I also hate spells that only effect a Total of X hitdice. A fireball does damage to as many targets as are in the Area of Effect, etc...

[Kalyth]

Kalyth wrote:

Mojorat wrote:

ALOT of conjuration spells are basically environmental effects. so you cast a pit on the ground the bad guys either walk into it or they don't you do not cast it at them. some conjuration spells like cloudkill do have limits though..

I would much prefer if these spells had a lesser effect on creatures of higher HD but still some effect.

Daze could instead stagger if the target was above the HD limit though I can see a HD limit on a Cantrip. But Daze monster really shouldnt have a HD limit at all. Heck as a 2nd level spell spending my action and a second level spell slot for a chance to cause one opponent to loose their actions seems pretty fair to me, no need for a HD limit IMO.

Sleep could fatigue a creature of greater than 4 hd, etc.... I just hate how the spell becomes completely useless. I also hate spells that only effect a Total of X hitdice. A fireball does damage to as many targets as are in the Area of Effect, etc...