Cast spell using higher level slot

[Herzog]

My (current) DM allows me to (spontaneously) cast spells using a higher spell slot when my lower level spell slots are used up. (Both artificer and bard).
It suddenly occured to me this might not be according to RAW.

Now, I know that you can accomplish the same with Heighten spell, but that Feat gives the additional benefit of actually improving the DC of the spell cast.

Am I being allowed something I shouldn't? Any references to rules or FAQ explaining either way would be appriciated.

 

[the Jester]

He's running it by the book. I don't recall off hand where the general rule is, but PH 178, upper right column under "Spell Slots" mentions that a wizard without high enough intelligence to cast his highest level slots must fill them with lower level spells. There is a general rule that says you can always use a higher level slot for a lower level spell, but I can't recall exactly where it is.

 

[Herzog]

Found it!

It's actually in the same block of text you referenced:

A spellcaster always has the option to fill a higher-level spell slot with a lower-level spell.

Although it is located under 'Preparing Wizard Spells', the generic reference to 'spellcaster' indicates it is a more generic ruling.

The location could be better, but the rule stands.

thank you!

Edit: the rule is repeated specifically for spontaneous casters in the Rules Compendium, page 139:

A spontaneous spellcaster always has the option to use a higher-level spell slot to cast a lower-level spell.