LAST EDITED ON 09-17-13 AT 11:10 AM (EST)It wouldn't work on lycanthropes in the majority of settings, but the first and third are generally accurate when this trope applies at all.
(The following is because I'm kinda bored.)
Remember the Vancian Magic trope? (He passed away recently. Readers mourned.) As the description on this one notes, a lot of the basis for this comes from Dungeons & Dragons, where spellcasters generally have to choose their spells for the day well in advance and can't pick new ones until the current spells have been used and they've rested for several hours. Well, with clerics -- the game's healers -- this was apparently always an extra-major problem. Not only did you basically have to be precognitive to know what you'd need on any given day, but most clerics would have to discard the game's information, scouting, defensive, and quirkier spells because what was the group gong to need? Healing. Lots and lots of healing. Constantly. As Rich Burlew noted, a cleric is generally seen as a walking first-aid kit. So most other spells never got used.
But the game evolved -- and eventually, clerics were given a singular ability. They could still memorize any spells they liked available at their power level from the lists, and memorization (or praying for them) was still required. But now they could spontaneously convert the energy from those castings into a raw jolt of positive force which would act as a healing spell. So they were free to keep all the lesser-used stuff ready to go, knowing that in a true emergency, they could use it all for healing anyway.
What this means in practical terms is that the follower of the divination deity, who has several dozen spells in his head all related to the gathering of information, absolutely useless in a direct fight, when cornered by undead -- is about to ruin their entire afterlife. Because against them, all those converted spells also work as direct attacks.
The CoDzilla trope (Cleric or Druid) exists for a reason.
As I understand it, the bad news is that nearly all such spells require physical contact -- and if you can hit them...