You mean where the party all dies at the end?
I've seen plenty of zombie fiction that includes survivors...most of it even.
That's not an argument against the 15-minute day. It's an argument that you need to keep back something in reserve for the end of the 15-minute day.
As others put it, if their casters have something left, classic 15 minute men keep going. They stop when the casters are out of spells, nearly regardless of other resources. By definition, they have kept nothing back at that point.
(In 4Ed, the triggering resource is supposedly Healing Surges.)
Gandalf is a literary construct
As are all the characters in the fiction you want to compare RPG games to.
If you want to say something is unlike the fiction-style play you advocate, you cannot criticize my point by saying I'm comparing something to a fictional character.
Gandalf simply doesn't cast spells left & right to solve problems. He casts spells if and only if spells need to be cast. Thus, he always has power to expend.
15 minute men don't. They cast and cast and cast. When the casters can't cast, the day is over, time to rest. (At least, so goes the oft-cited description of play.)
I'm sure some do, as do some non-15 minute men
By definition, no.
What happens if I do as you suggest, and after firing my crossbow at the monsters (5% chance of doing 1d8 damage - avg. 0.2) instead of my Magic Missile (5d4 guaranteed damage - avg. 12.5) and the monster brings down our lead fighter?
Knowing the guy who plays
our mages?
His response would probably be that your Mage:
1) chose his spell list poorly
2) chose the wrong spells to memorize/cast before backing off the accellerator
3) chose the wrong targets for his spells
4) stopped casting at the wrong time*
5) the fighter got unlucky and/or prevented you from casting the spells you should have been casting
...in some combination. (Because he tells me that when
I step into his backyard and play a spellcaster.)
He's been doing this since 1985, and it's yet to pop up often enough to worry about it.
* to clarify, the figure I stated is an estimate. The point is that he does not keep casting spells every turn. He has an initial burst of casting, then pauses, switching to weapons/going to standby. If and only if the battle turns against the party does he resume casting. Once the battle is in hand, he stops casting. End result: he nearly always has something nasty available to cast, even in the 6th encounter of the day.