Can you target someone being grappled with Otiluke’s resilient sphere?

Does Rod of Pact Keeper increase the DC of all spells if I am a Warlock/Sorcerer?

Does Zone of Truth work in combination with Speak with Dead?

Does Change Shape work same as polymorph spell?

Can you get a bonus to AC from either a magic shield or magic armor?

If a ghost possesses a magic-user, can it cast spells?

Would a wildshaped druid/monk be able to use his Ki features?

Do you have to declare Sneak Attack or Divine Smithe beforehand?