Magus Archetype Question

[Rayek]

Hi,
I am not quite sure if I found the right forum for this, as I need advice, a general rule answer as well as 3pp rules answers and advice^^

One of my player wants to play a magus and wants to use these archetypes:
Extempressario
Cabalist
Now both of these change magus spells, one modifies knowledge pool and the other replaces it.
At the moment I would tend to allow it, using the following ruling:
Spells get changed as written in the Extempressario.
Knowledge Pool gets replaced as written the Cabalist.

Now my Question is:
Does that solve my issue or is there anything I am overlooking?
And secondly:
In my opinion these archetypes make him a bit weaker, but that might just be my own limited knowledge. Would allowing this make him (a lot) more powerful?

Thanks in advance,
Rayek

[Saivlin]

The general rule is that archetypes that modify the same class features can't be used together.

If you're going to allow that, then using Extempressario for the changes to spells (Force of Personality, Spells and Cantrips), Spell Reserves (replacing Spell Recall), and Improved Spell Reserves (replacing Improved Spell Recall) while using Cabalist for Bloodline Power (replacing Knowledge Pool) and Bloodline Spells (replacing Greater Spell Access) seems like it would work.

By using the Bard casting progression, the magus would have one extra spell per day of each level. A well chosen bloodline can provide a great selection of spells, if the campaign reaches a high enough level for Bloodline Spells to come online. With the general reliance of magus on a small selection of lower level spells (Frostbite, Shocking Grasp, Frigid Touch) to power their terrific burst damage, either archetype on its own will allow the magus to do an extra burst. Additionally, Extempressario allows spell recall to include metamagic, which makes it strictly better than the vanilla magus' Spell Recall and Improved Spell Recall. The loss for the magus is the reduced versatility of spells known. The magus loses knowledge pool and greater spell access, and becomes limited to a relatively small selection of spells known.

Generally, this means that you can probably expect more Intensified Shocking Grasps in combat, and less versatility out of combat. The reduction of non-combat versatility is made more extreme by switching the spell casting stat from Int to Cha. This will mean the magus gets far fewer skill points.

tl;dr - The magus will be stronger in combat, but have less non-combat utility.

[taks]

Per RAW (including the FAQ clarification), archetypes that modify the same class ability in any way cannot be used together. This includes something as simple as adding a spell to the list of spells known, or a feat to the list of feats available. Since they both change magus spells, they are incompatible. Since they both modify knowledge pool, they are incompatible.

As a GM, you are welcome to allow whatever you want, but this is the rules forum, and rules answers are what you will get.

[Arcane Addict]

RAW the two archetypes cannot be taken together because they both change the same things. I'm not so sure from your post whether you're aware of this. That said, its for your homegame, not PFS so you're free to make allowances.
Basically, by allowing this you've created a Sorceror variant of the Magus that is better than the official one. That one sucks though so I see no issue with it. I also agree that it'll likely be worse than most other types of Magus, though I cannot say so with absolute certainty, depending on the Bloodline and how he plans to advance his character.

If, for some reason, you still don't feel comfortable you could suggest to allow it for X sessions or levels during which you can still change your mind. Whatever happens keep an open dialogue going with your player.

[Rayek]

@Saivlin First of all, thanks for the extensive answer. You confirmed most of my thoughts, but as long as I am not missing something, both bard and magus recieve the same amount of spells per day?

@taks Thanks for the answer. What would have been a more appropiate subforum to post the question with my intention?

@Arcane Addict Thanks for your answer. I will keep an open dialogue as you suggested. I'm mostly confident about it though, was just checking if I am overlooking potentially OP combos.

[taks]

Nothing wrong with this forum, you'll just get more rules specific answers here - you did ask a rules question, after all. The Advice forum (among others), however, may net you more involved answers w.r.t. options.