What counts as magical item?

[Dexter]

I'm planning challenge run were I will stick to 5E rules for magical items. Meaning, 3 magical items max on person plus no Draconic Elemental Weapon shenanigans, long resting in trully save spaces and no teleporting around to get to those safe spaces.

However, I am not really familiar with D&D rules and I do not know what counts as magical item. Also, if You have any other suggestions how to transfer those rules to BG3 feel free to voice them here ;)

[Shale]

I can give you some guidelines, but unfortunately 5e doesn't have any strict rules on which magic items are required to be attuned. Sometimes a really good item can be used freely while a similar item might need to be one of your 3 attuned items.

+1/2/3 weapons, armour and shields that have no other abilities don't ever require attunement. If the item grants a minor benefit, it's probably safe to say that doesn't require attunement either.
If an item grants resistance to a damage type, boosts your stats, lets you use a spell of 2nd level or higher, or some other effect that seems as good or better than those, it probably would need attunement.
Also if a weapon adds at least 1d6 more damage than usual, that's probably attunement too.

Unfortunately it will come down to your own judgement. If you want to take that out of the equation, you could just any items of certain rarity count (aside from basic +# weapons and armor, which should never require attunement).

[Dexter]

Originally posted by Shale:

I can give you some guidelines, but unfortunately 5e doesn't have any strict rules on which magic items are required to be attuned. Sometimes a really good item can be used freely while a similar item might need to be one of your 3 attuned items.

+1/2/3 weapons, armour and shields that have no other abilities don't ever require attunement. If the item grants a minor benefit, it's probably safe to say that doesn't require attunement either.
If an item grants resistance to a damage type, boosts your stats, lets you use a spell of 2nd level or higher, or some other effect that seems as good or better than those, it probably would need attunement.
Also if a weapon adds at least 1d6 more damage than usual, that's probably attunement too.

Unfortunately it will come down to your own judgement. If you want to take that out of the equation, you could just any items of certain rarity count (aside from basic +# weapons and armor, which should never require attunement).

And that's pretty much my thought process summed up.
Weapon that allows for magical attack = attunement (non magical attacks are fine, like Very Heavy Greataxe etc)

Now I do not know what to do with weapons such as Jaheira's Sylvan Scimitar (uncommon +1 Scimitar that allows its wielder to use their Spellcasting Ability modifier instead of their Dexterity modifier to determine their Attack Roll bonus. )
Sounds like magic... and similar minor bonuses like: allowing to cast a spell with bonus action after attacking