I wondered how on earth the Trick Magic Item feat works with items if you have a spellcasting archetype?
The same way it works if you don't have a spellcasting archetype. The difference effectively comes down to if the GM will let you use Trick Magic Item on items that you can instead cast from your spellcasting archetype.
I wanted to know how the above feat would work with a wand that has a spell on both the Arcana and Occult traditions? Specifically can I still trick the wand to coax a higher proficiency out of it than "Trained" since I'm now Master in Occultism and will eventually be Legendary before the end of the campaign, thus getting to treat it like "Expert" spellcasters do
Wands use your spell attack bonus and spell DC. Whatever that happens to be. In your character's case, you could cast from a wand with an Occult tradition spell using your Bard spellcasting proficiency.
If you activate the wand using Trick Magic Item you would be calculating your spell attack bonus or spell DC using the calculation in Trick Magic Item.
If you activate a magic item that requires a spell attack modifier or spell DC and you don’t have proficiency in the relevant statistic, use your level as your proficiency bonus and the highest of your Intelligence, Wisdom, or Charisma modifiers. If you’re a master in the appropriate skill for the item’s tradition, you instead use the trained proficiency bonus; if you’re legendary, you instead use the expert proficiency bonus.
I think what you are getting at is that your character does have proficiency in Occult spellcasting, so they would have the proficiency the wand requires and so TMI wouldn't override the spell attack bonus and spell DC that you already have ... even though the TMI calculation might be higher than what you are getting from Bard Archetype.
That is a GM call. The GM might rule that you can cast the wand using the Arcane spellcasting that the wand's spell has instead of Occult and use TMI to cast it with at that point. Or the GM might follow the strict letter of the rules in Trick Magic Item and not let you use the TMI calculation on any spellcasting item that could be cast using Occult spellcasting and insist that you use your Bard archetype spellcasting proficiency for it.
Or the GM might run it the way that I would, and let you use the TMI calculation any time that you are willing to spend the action cost and skill check to use TMI to cast from the item with.
You would also need the 4th level feat, Basic Bard Spellcasting. But yes, Expert Bard Spellcasting will give the character Expert proficiency in Occult spellcasting to match what they could get from Trick Magic Item.
In addition to a handful of spell slot spells from both feats.
There's almost certainly going to be GM variance on this, but I'd rule no.
If you activate a magic item that requires a spell attack modifier or spell DC and you don’t have proficiency in the relevant statistic, use your level as your proficiency bonus and the highest of your Intelligence, Wisdom, or Charisma modifiers. If you’re a master in the appropriate skill for the item’s tradition, you instead use the trained proficiency bonus; if you’re legendary, you instead use the expert proficiency bonus.
The problem here is the first line. You DO have proficiency in the relevant statistic since Bard Dedication gave it to you. At this point you're not meeting the condition stated, so what comes afterward doesn't apply.
Back in the premaster days where you'd get trained just in Occult spellcasting proficiency, you could have argued using Arcana would be valid since you're not trained in Arcane spellcasting proficiency. But in the remaster it's just one proficiency as stated in the dedication: "You’re trained in the spell attack modifier and spell DC statistics."
I'm playing a Scroll Thaum who picked up Bard archetype thinking stupidly I could advance my proficiency with a single tradition so I could get away with 3-activity spells on a given turn. It didn't work out, but I kept the archetype as the cantrips were really helpful in some of the battles. I wanted to know how the above feat would work with a wand that has a spell on both the Arcana and Occult traditions? Specifically can I still trick the wand to coax a higher proficiency out of it than "Trained" since I'm now Master in Occultism and will eventually be Legendary before the end of the campaign, thus getting to treat it like "Expert" spellcasters do (assuming I survive as the character's been through the River of Souls a few times like a punching clown)? Stolen Fate is a serious gauntlet sometimes....
Fraid not. The good news is that Expert and Master Bard Spellcasting will up your proficiency to Expert/Master, and that applies to all wands regardless of school.
That is a GM call. The GM might rule that you can cast the wand using the Arcane spellcasting that the wand's spell has instead of Occult and use TMI to cast it with at that point. Or the GM might follow the strict letter of the rules in Trick Magic Item and not let you use the TMI calculation on any spellcasting item that could be cast using Occult spellcasting and insist that you use your Bard archetype spellcasting proficiency for it.
RAW, Spellcasting proficiencies are singular and apply to all traditions since the remaster, so "letting you use Arcane spellcasting" doesn't actually change anything here. You're still trained in spell attacks and spell DC and so TMI doesn't let you override them.
The GM can ignore the condition in TMI, but if they're doing it for Arcane vs Occult doesn't actually matter.
RAW, Spellcasting proficiencies are singular and apply to all traditions since the remaster, so "letting you use Arcane spellcasting" doesn't actually change anything here. You're still trained in spell attacks and spell DC and so TMI doesn't let you override them.
The GM can ignore the condition in TMI, but if they're doing it for Arcane vs Occult doesn't actually matter.
Ah, that's right. I keep forgetting that change.