2 rules questions

[AttilatheYeon]

1. If i get a magic staff, do i need to have the spells on my class spell list to cast them from the staff? For instance, i'm a warlock who got a staff of spiders, can i cast web from the staff even though it's not on my class list?

2. If i'm a multiclass spellcaster, how do i determine which spellcasting attribute to use? For instance, i'm a cleric/bard who casts dissonent whisper, do i have to use charisma or can i use wisdom?

[Ninja_Prawn]

1. If i get a magic staff, do i need to have the spells on my class spell list to cast them from the staff? For instance, i'm a warlock who got a staff of spiders, can i cast web from the staff even though it's not on my class list?

2. If i'm a multiclass spellcaster, how do i determine which spellcasting attribute to use? For instance, i'm a cleric/bard who casts dissonent whisper, do i have to use charisma or can i use wisdom?

1. Nope. Unless the item says "requires attunement by a wizard", a warlock can use it.

2. You use whichever class you learned the spell as. You need to track your bard spells separately form those you're using from the cleric list. You could even pick the spell twice and have the choice between both stats, if you really wanted to.

Except that Dissonant Whispers is not a cleric spell, so it's kind of a bad example.