Trick Magic Item https://2e.aonprd.com/Feats.aspx?ID=857

Easy Utility: Assurance + Expert Arcane + Trick Magic Item https://www.reddit.com/r/Pathfinder2e/comments/pepmdv/easy_utility_assurance_expert_arcane_trick_magic/

https://docs.google.com/spreadsheets/d/1A5RptcITraMlJ7db_wilQVqSF_UNJZhxcLNM-vvSUYg/edit

Setting the DC:

https://paizo.com/threads/rzs4316z?Trick-Magic-Item-DC https://paizo.com/threads/rzs43aua?Trick-Magic-Item-DCs

According to the list of magic wands, a wand of a 1st-level spell is level 3. Going to level-based DCs, that would be a DC 18.

Scrolls seem to be easier to trick. A 1st-level scroll is a level 1 item, so the level-based DC would be 15.

Level-based DCs https://2e.aonprd.com/Rules.aspx?ID=554

How do Scrolls work?

https://www.reddit.com/r/Pathfinder2e/comments/cuea5o/using_scrolls_and_wands/

How do Wands work?

https://2e.aonprd.com/Rules.aspx?ID=756

Wands contain a spell that can be cast once per day.

https://www.reddit.com/r/Pathfinder2e/comments/109hh8o/basic_advice_to_anyone_wanting_to_play_a_caster/

How do Staves Work?

https://2e.aonprd.com/Rules.aspx?ID=748

Requirements to cast a spell from a staff:

• You have that spell on your spell list
• Are able to cast spells of the appropriate level
• Expend a number of charges from the staff equal to the spell's level

https://www.reddit.com/r/Pathfinder2e/comments/109hh8o/basic_advice_to_anyone_wanting_to_play_a_caster/ https://www.reddit.com/r/Pathfinder2e/comments/f5d9n3/question_about_wands/

Even if you don't have access to spellslots, a Staff still has some value -- you can still cast cantrips from that Staff.

Preparing a Staff

You can only prepare one staff during your daily preparations and a staff may only be prepared by one person per day. Add charges the staff equal to the level of your highest-level spell slot (e.g. if you can cast 5th level spells, you add 5 charges to the staff). These charges are lost after 24 hours or if a new staff is prepared.

Magic Items to Look For

Ring of Minor Arcana https://2e.aonprd.com/Equipment.aspx?ID=478

By Level

Ideally, you want the level to be less than or equal to your Assurance level.

Assurance no longer works with level 19 checks.

By Spell Level

Spell Slot Progress for Classes and Dedications (Useful for knowing how many charges a staff gets during daily preparations)

Spell Progression For Archetypes: https://www.reddit.com/r/Pathfinder2e/comments/mhtp3p/spell_slot_chart_for_archetypes/

Summary

An Expert in Arcane, Religion, Nature, or Occultism is effectively as effective at casting spells as a character who took a Dedication Archetype with that spell list.

FAQ

Are you able to cast a spell from a Dedication without the Basic Spellcasting Feat?

Yes, you can use scrolls and magic items from that class's spell list once you have the Dedication. The Dedication provides your character with the ability to cast spells from the spell list, you just don't have access to spell slots until you get the Basic Spellcasting feat.

Can you cast spells with a wand that's higher level than your character? https://www.reddit.com/r/Pathfinder2e/comments/jtsjwu/can_you_cast_spells_from_a_wand_that_is_over_your/ https://www.reddit.com/r/Pathfinder2e/comments/ecwr5a/using_higher_level_scroll_spells/

Things get a little weird with comparing this Trick Magic Item stragegy with Spellcaster Dedications. As long as the spell is on the caster's spell list, they are able to cast the spell using a scroll or a wand -- there is no check. Dedications will always be more effective at casting higher level spells than a Trick Magic Item character but it's also somewhat unlikely you will receive items that much higher than Assurance can handle.

Is the Scroll Trickster Dedication worth it (or just better)?

It could be but the Scroll Tricker Dedication is designed for someone who already has access to a spell list. It might sound weird but the Archetype Class Feats, like Skim Scroll and the Caches, work better for casters that already have access to those spells.

The whole justification of taking Trick Magic Weapon and Assurance is to use the Free Archetype feats for something besides a Spellcaster Dedication. Skim Scroll allows you to cast spells from scrolls with 3 actions instead of 4, so it's almost a requirement if you want to use scrolls in combat (almost always a bad idea).

What are the best ways to get the Cast a Spell Action?

https://paizo.com/threads/rzs43g4b?DedicationsArchetypes-and-scrollsStaveswands https://paizo.com/threads/rzs42xdc?Staff-usage-in-PFS2

Any Spellcaster dedication will get you access to a spell list at level 2; Eldritch Trickster Rogues and Ancient Elves can get these Archetype Dedications at level 1.

https://www.reddit.com/r/Pathfinder2e/comments/zxggfp/eli5_using_staves_as_a_spontaneous_caster/