CommentWhat are your personal processes for when you find you need to make up an encounter on the fly?I usually throw stuff at the players with CR in mind – if it’s something on the fly that’s just meant to be a quick fight, I use creatures with a CR at about half or less of the party’s level, no more than 3 – 5 critters. That usually seems to work. For a bigger monster, I just keep the CR at or less than the party’s level. from discussion D&D AMA with Mike Mearls and Chris Lindsay 1/15.