Quote Originally Posted by Kurald Galain View Post
I don't see a problem with that; I'd call it a high-risk high-reward move.
High risk?

Bull. Sacrificing a turn on a gamble is not "high risk", especially when you it costs the same as other options available to you. That implies some kind of backfire or effect which is not just outright wasting a turn or winning. High risk would be if these spells had ranges of "touch" and there wasn't a way to boost your range, or they applied some additional effect on you afterwards making protracted defense or mobility harder.

Assuming, of course, that you don't get to resolve the entire plot or kill the Big Bad just like that. The thing is: don't assume the PCs are fighting one monster. Assume they're fighting ten, and suddenly it's much less of a problem if they petrify one of the monsters.
The issue doesn't change when you add more guys, but okay, they're fighting ten guys. The Wizard player spends 1 resource to instagib 1 guy, but his mechanically identical counterpart the Rogue is fighting will require him to spend 4 times as many resources fighting him before he dies, with the same amount of resources the Wizard could kill three more guys (assuming they fail their saves). That's why I said "disproportionate effort", because the effort expended for effect gained is vastly undercost, at best. And if everyone has them, so they aren't undercost, you've created a game where if an enemy doesn't have explicit immunity to SoLs they are mooks.

Now using SOL spells against PCs does need more thought, because the DM declaring that "you cannot fight now" is not good for gameplay (although it would surely be mitigated if combats play out much faster, or if other PCs have decent countermeasures).
Mitigated sure, but that's not going to make it better design, it's just going to make the bad design less tedious. Short of designing the game so that the player is never removed from play, he just has different options available to him, you're never going to be able to solve the player agency issue that SoLs by default cause.