could someone explain to me how this metamagic feat is used in practice? i don't understand the benefit
It is a higher level spell, so its DC is higher.
Heighten Spell makes a level act as a higher-level spell.
Take, for example, a first level spell. Using Heighten Spell, you prepare it as a 3rd level spell. When you cast the heightened spell, it acts as a third level spell in terms of determining Save DC.
The benefit to this metamagic feat is primarily to help get through Globes of Invulnerability and Spell Resistance, It can be useful for making Fireballs harder to avoid, as well as make any spell with a save involved harder to shrug off.
Level doesn't have anything to do with SR. The main points of increasing the spell level are:
Save DC
Getting through Globes of Invulnerability
Spell level-based things like determining whether a Darkness cancels out a Light or not.
My bad. I haven't played d20 fantasy in a while. Edited!
seems like kind of a lousy metamagic feat
Quote from: tleilaxuseems like kind of a lousy metamagic feat
Not really.
Take charm person. At 20th level, your average opponent will be unaffected by it because the save is so low. Heighten it with a 9 level slot, and you have just increased it's ST DC by 8. All of a sudden your enemy NPC's are much more suceptible to be under your control.
Quote from: TrainzNot really.
Take charm person. At 20th level, your average opponent will be unaffected by it because the save is so low. Heighten it with a 9 level slot, and you have just increased it's ST DC by 8. All of a sudden your enemy NPC's are much more suceptible to be under your control.
Or you could use Dominate Monster instead, which is 9th level to begin with. Or if you just want them Charmed for some reason, Mass Charm Monster which is 8th.
It's of very limited use, really. The example I've seen of how it can be useful is Sanctuary -- if you crank up the save DC by all means possible (including Heighten), your healer can be virtually untouchable. It's pretty gimicky and metagamey, but that's 3e for you. :)
In general, though, Heighten is one of those feats that you have to be clever to get good use out of.