How can I prepare for creatures with damage resistances or damage immunities?
I saw a lot of questions floating around the Stack about damage Immunities and Resistances and troubles therein for players (Lycanthropes, and Puddings, and Ooze, oh my!). I hoped to create a unifying question so that we could stop dealing with all of these ad-hoc things and just point to a single answer (as the answers are all usually the same sort of "prepare better, know your enemy").
The inspiration was another one-stop-shop question for forced movement, provided by Rubiksmoose: Can I trigger an Opportunity Attack by forcing an opponent to move out of my reach?
Can my question either be reopened as-is, or is there something that we can do to make it Stackable, while also keeping my original intent?