Really comes down to implementation and encounter design. For example, you could play all of Dark Sun: Shattered Lands without touching Fog Cloud, but good luck beating the final battle without it. That LOS breaking and the tunnel-vision-of-death it creates is priceless. Obviously, you want to add Entangle to the mix too, but Entangle is generally more widely useful in games.
Fog Cloud in general: useless since you're better off with offensive spells that will kill the shooters instead.
Fog Cloud in an encounter with a lot of powerful archers/wizards: life saver.
I'm convinced a lot of generally obscure spells could be redeemed with creative encounter design. And even if a game makes an obscure spell shine just once, that's good enough for me as it makes the battle memorable, like the one described above.
Also special mention to all those wizard vs wizard spells generally made irrelevant because in party-based games, wizards just don't have the time to 1v1. Yet, BG2 has this wizard duel arena in the drow village. It was super refreshing to explore all those invulnerabilities, reflects and magic piercing options.
Fog Cloud in general: useless since you're better off with offensive spells that will kill the shooters instead.
Fog Cloud in an encounter with a lot of powerful archers/wizards: life saver.
I'm convinced a lot of generally obscure spells could be redeemed with creative encounter design. And even if a game makes an obscure spell shine just once, that's good enough for me as it makes the battle memorable, like the one described above.
Also special mention to all those wizard vs wizard spells generally made irrelevant because in party-based games, wizards just don't have the time to 1v1. Yet, BG2 has this wizard duel arena in the drow village. It was super refreshing to explore all those invulnerabilities, reflects and magic piercing options.