Undercasting and Magical Lineage

[Negative Zer0]

So lets look at an easy example of Undercasting:
You have a level 6 Psychic
One of your 3rd level spells is Mind Thrust III
You do not have Mind Thrust I or II in your spell list at all.

With undercasting this means you can Cast Mind Thrust III as Mind Thrust II and in doing so they use a 2nd level spell slot and do damage as Mind Thrust II. You can also cast Mind Thrust III as Mind Thrust I and use a level 1 spell slot.

So here's where the question comes in, I have Magical Lineage on Mind Thrust III. I undercast Mindthrust III as Mind thrust II and apply Disruptive Meta Magic. Dose lineage still affect this cast?

I imagine the answer is NO but I wanted to ask to be sure.

Undercasting:

Some psychic spells can be undercast. This means that
the spellcaster can cast the spell at the level that he
knows, or as any lower-level version of that spell, using
the appropriate spell slot. When a spellcaster undercasts
a spell, it is treated exactly like the lower-level version,
including when determining its effect, saving throw, and
other variables. For example, a psychic spellcaster who
adds ego whip III to his list of spells known can cast it as
ego whip I, II, or III. If he casts it as ego whip I, it is treated
in all ways as that spell; it uses the text and the saving
throw DC for that spell, and requires him to expend a
3rd-level spell slot.
Whenever a spontaneous spellcaster adds a spell to
his list of spells known that can be undercast, he can
immediately learn a spell in place of each lower-level
version of that spell he knows. In essence, he loses each
earlier version and can replace it with another spell of the
same level that is on his spell list.

[Imbicatus]

No. You are not casting Mind Thrust III, you are casting Mind Thrust II. They are separate spells, and Magical Lineage on Mind Thrust III would not apply.

[ZZTRaider]

Hm. I'm not sure that's correct, actually.

Undercasting (emphasis mine) wrote:

This means that the spellcaster can cast the spell at the level that he knows, or as any lower-level version of that spell, using the appropriate spell slot. When a spellcaster undercasts a spell, it is treated exactly like the lower-level version

I think "as" is the key word here. You're not instead casting Mind Thrust II, you're still casting Mind Thrust III but is acting as Mind Thrust II, including the spell slot used.

It goes on to state that the undercast spell is "treated like the lower-level version", further reinforcing that you're still casting the higher level spell.

I'd expect table variation on this one.

Regardless, if this is a home game, a permissive GM may allow you to take Magical Lineage on the entire Mind Thrust line, rather than a specific iteration of it.

[LazarX]

Negative Zer0 wrote:

So lets look at an easy example of Undercasting:

You have a level 6 Psychic
One of your 3rd level spells is Mind Thrust III
You do not have Mind Thrust I or II in your spell list at all.

With undercasting this means you can Cast Mind Thrust III as Mind Thrust II and in doing so they use a 2nd level spell slot and do damage as Mind Thrust II. You can also cast Mind Thrust III as Mind Thrust I and use a level 1 spell slot.

So here's where the question comes in, I have Magical Lineage on Mind Thrust III. I undercast Mindthrust III as Mind thrust II and apply Disruptive Meta Magic. Dose lineage still affect this cast?

I imagine the answer is NO but I wanted to ask to be sure.

** spoiler omitted **

The answer is no... the ONLY purpose for undercasting is to let psychics who only have a limited number of known spells be flexible in using the psionic attack and defense spells without having to know versions 1-5 of every one of those spells. When you undercast Mind Thrust 3, your are casting 2 or 1. which are second and first level spells. You can not use shenannigns to cast a 2nd level spell as a first level spell or a knack.