I may have been sleep deprived off my mind, but I once recall reading about an item that allowed a spellcaster to prepare spells of a spell level not normally accessible to them (for example, an 11th level spellcaster preparing 7th level spells). I'm trying to find it again and cannot, for the life of me.
I think I recall the item having very specific limitations, such as losing spells if you left the item's area of effect or duration. I also think it was an incense of some kind, though searching that term doesn't seem to bring up the item I think exists.
Has anyone heard of this item?
I don't think so. I had to create something like that for the last campaign I ran, a sort of magical fuel source that could be burned for greater magical potential than normally possible. Thus we had a gate-powered constructed and piloted by a 9th-level wizard. Granted, that was some time ago, so maybe something new got printed.
Maybe it's a Candle of Invocation
First you have to be able to Learn spells above your level.
If you want it, cool.
I was in a campaign where rituals allowed you to cast above your level, and it worked out fine, but she was a very good GM. This should be the same, more combat suitable, and a constant threat to be abused and out of control. Depending on your crew, this could easily make non-casters less relevant, so using it as more than a plot device is likely to be trouble. If you have a pushy caster player, (is there any other kind in PF?), it is going to make more of a God Wizard, or Dr. Who with his, now hers, piloted TARDIS gate.
Oh, I lost my track, perhaps scrolls might be a more controllable and less abusable option, and less likely to cause strife.
The only item I know of that does that is an artifact called the egg of the phoenix which I'm not even sure is in pathfinder.
It was a puzzle box Which had multiple stages that were progressively larger and harder to solve then the previous stage. Opening a stage would give you the ability to use spells regardless of level or class. Each stage was a harder check but granted more powerful spells then the previous stage.
Oh yeah, and each time you opened a stage it would hit you with a fireball like effect that bypassed all forms of resistance and immunities with each stage doubling in damage. So, even if you were smart enough to open the thing you might not survive the damage.
I think you also had to either physically hold or be within a certain range of it to benefit from it. Which meant that if you opened it beyond the 2nd stage it became too large and unwieldy to easily travel with.
As far as consumables go, I know there are consumable items that raise your caster level. But those kinds of increases don't increase your spell progression, though I can easily see how it could be mis-read in that way. A first level wizard can have a caster level of 5, but they still won't have anything but first level spells to work with.
Edit: Just read Candle of Invocation and it seems to be the item you are describing.
Maybe it's a Candle of Invocation
Oh yeah, that thing. That could be it.
You can't create scrolls of spells you can't cast.
Sure you can. You just someone else to provide the spell.
As for items, I seem to recall some specialty spellbooks that allow extra spells or added meamagic to spells. Not consumable, but such does exist.
Another thought was the Manual of Golem Creation that is consumed in making the golem, and included the spells needed. This was often including spells you cannot cast at the time you use it.
/cevah