Party wanted to attach a chest to Paladin’s horse, then dismiss mount to hide item. Possible?

Can monsters immune to the grappled condition make grapples themselves?

Can the Undead Thralls feature of a necromancer be applied to Create Undead as well?

How many spells can fit into a Ring of Spell Storing?

Fighter’s “Know Thy Enemy” let’s players learn the target’s level. Where’s that information located?

Is the general rule to round up or down when doing calculations?