| You might encounter mobs that have special abilities like charm, slow or whatnot, which you might assume is save vs. MR or DR etc. But once you discover the ever-useful lucy.fnord.net site, you might find yourself assuming it is the wrong resist for that particular mob (cursed charm is DR, and not MR for example).
I guess it stems from the pre-Velious era where fear and charm was almost (?) always MR, and you basically knew what type of resist gear to bring to the encounter. |