They nerfed it that much? See, this is when rules need to be ignored.
it's not that they nerfed it per se, but it's the HP of monsters that has increased.
in 2e, fireball is 5-10 d6 damage. Ogre has about ... 4HD+1 in hp, so on average about 20 hp? Even a 5d6 fireball has a decent chance of killing an ogre.
In 5e, a fireball is a flat 8d6 damage. If you want to make it more powerful, you cast it as a level 4, 5 etc spell. It's not exactly nerfed. BUT the average ogre has ... 78 hp if my memory serve? So it can easily survive 2 fireballs.
I'm writing this away from my books so the numbers may be a bit off, but the broader picture is correct.
A 78 hp ogre? Wow! Didn't know that. Thanks!!!
Yeah, I haven't bought new D&D books since about 2001, so I'm out of the loop....
The power loss of evocation has been over several editions, and has gotten rather stark in 5e.
I was looking at ogres the other day. In 2e a fireball had a pretty good chance of killing an ogre. In 5e you will need *three* fireballs *if* the ogres fails all saves! In other words, if the party is being charged by 4 ogres, in 2e fireballing them is going to make a huge difference. In 5e... it's mostly going to make them angry, there are far better spells you could cast on them to help your party win.