On the old threads talking about game design, wizards, literature, nerfing wizards, etc..., I've posted a few times that while I know that wizards and other spellcasters tend to have a lot of potential options, in actual game play that doesn't tend to make them all powerful.
But that's just my experience.
Golems, devils, demons, and all sorts of other beasties have too many resistances and SR. In older editions, MR was worse.
But again, this is just my experience.
In your experience, are wizards the masters of the universe or just squishy dudes that until they hit 15th level must hide for life itself?
It's a little of both. It depends on the edition and the GM. But IMO in 3.x, which I have a lot of experience with, wizards got overpowered at the higher levels when they didn't seem to run out of spells per day. And I'm talking three or four encounter days here, not 15 minutes.
In 2e and 3e, the power curve was steep. A 1st-level wizard had very few spells per day. Whether they rocked or not depended heavily on spell selection.
For instance, a 1st-level wizard in 2e with sleep was amazingly powerful until they'd lost that spell. Low-level enemies had very weak saving throws. Unfortunately, afterward you were reduced to throwing darts. IIRC you could throw three a round, and that wasn't too bad, as long as you had a good Dexterity score, and you couldn't rely on that.
At higher levels your direct damage was powerful, as enemy hit points were weak. Unfortunately, so were yours. Fireball was king. Enemy saves were creeping high enough that they often didn't fail.
At even higher levels opponents had very good saving throws. That's when you started dishing out Power Word X spells, which had no saving throws and had very fast casting times too.
A note on casting spells: if you took even one point of damage, your spell fizzled, and the initiative plus casting time system made it fairly easy for enemies to do something about this.
My 2e experiences are rather hazy. I recall kicking butt due to use of Stoneskin, but didn't that have an expensive material component? I suppose Improved Invisibility was really good though. Short of clever tactics, there wasn't much a non-spellcasting enemy could do to you.
In 3.x the curve was a little less steep. At pretty much all levels, save-or-suffer was better than direct damage due to hit point inflation.
Unlike in previous editions, you could control your save DC. Your highest stat was your spellcasting stat, which meant you could drop your highest save DC on whatever save you wanted to target (as long as you had higher level spells). If you were targeting an opponent's strong save (eg a fighter's Fortitude save) your chances of success could easily be more than 50%, since your opponent isn't boosting their Con every level. Indeed, only Dex and Wis-based classes got a lot of power out of the new saving throw system (enchanting a cleric was basically impossible). Of course, you would try to target your opponent's weak save. Target a "big dumb fighter" or "big dumb monster"'s Reflex or Will save; target a "controller"'s Fortitude save, and you were usually ahead of the game. (Usually, turns out that ogre was a spellcaster and had a high Will save!)
At higher levels, this got marginally better.
Defense spells had a few really powerful numbers in there. Spells that boosted a stat (like Mage Armor) usually weren't worth casting.
Once you reached 3rd-level, you might prefer Mirror Image (works against any enemy without special senses, and it doesn't matter if their attack bonus is twenty points higher than your AC). Also
really handy against targeted spells (Magic Missile, Finger of Death, what have you).
At 5th-level you got Fly, which blunted or even eliminated many opponents' attacks. Displacement was also a cool choice, but Mirror Image was probably better. Half the time your opponent's attack bonus didn't matter.
At 7th-level you could get Greater Invisibility, which was probably broken as written; the rules for targeting an invisible opponent were so slow, arcane (no pun intended) and biased in the mage's favor it basically made you invincible. Your opponent could turn the tables with See Invisibility or True Seeing, in which case you only had one opponent to deal with for a bit, and I would suggest killing that guy and fast! (Did Nondetection work to keep you from being seen here? I thought so, but never actually got to use this tactic.)
So in short, use defenses that completely overrode opponent's attacks. Most monsters couldn't handle this, and even when facing evil classed NPCs few opponents could deal with this.
Mage's defenses were pretty fragile against magic, however. One area dispel and your flying invisible mage might be falling (or floating down), visible and sporting a very low AC. Against non-spellcasters, you were sitting pretty. Unless you got surprised, of course, but that's something you could use against opponents too, so it's a wash (IMO). While wizards could slather on a suite of defenses when they had time, your best bet was to use illusory defenses (Greater Invisibility or Mirror Image) for your one-round "screw-non-spellcaster" defenses.
Possibly worse was Spell Turning. You never really knew which enemy had it on, and even if you knew the enemy wizard had cast it, you didn't necessarily know on who. (But evil wizards tend to be selfish, so assume they cast it on themself. Which was a problem when they also used True Seeing, since you couldn't instantly eliminate them. But note that a fighter can't really do anything about this.)
Spell Resistance could ruin a mage's day. Sometimes. Using just PH1 spells in 3.5, you could bypass SR in numerous ways. Conjuration was the key here. If you dished out spells like Glitterdust (cast it at 3rd-level when SR-sporting enemies were very rare, keep casting Heightened versions at higher levels) or Otiluke's Resilient Sphere you always had something to do when facing demons, golems, etc. These were great spells too, so there's little reason not to pick them. On the other hand, loading up exclusively on such spells was problematic to say the last. If you're only prepping Glitterdust, expect to run into lots of enemies with blindsight.
Utility spells were the sort of thing that could drive other players nuts. While some (Fly) didn't bother me too much (you can fly, but not your friends, and being far from them meant you were vulnerable to invisible stalkers, etc), others, like Teleport, could break campaigns. While DMs had to take that into account as PCs gained levels, I think many wished it were of higher level to start with. And some spells (Polymorph, Shapechange) needed a complete rewrite. In fact, broken spells were usually worse than broken feats, if only because spells were more powerful than virtually anything else in the game.
I might be conflating the wizard with the druid here, but IIRC a wizard could summon a unicorn, who could provide some limited healing (not great in a fight, but really good afterward) and give you free Protection from Evil to boot!
Concentration was an amazing skill. You could use it to guarantee you wouldn't draw an AoO when casting a spell, and after a while casting on the defensive became automatic. You could "take 0" and still never fail. Other distractions were generally pretty weak and easily ignored. However, the skill was still rolled whenever someone readied an action to hit you or drop a fireball on you when you cast a spell, or you were taking ongoing damage, or were grappled.
IMO, the wizard's advantages in 3.x were considerable:
1) Very powerful save-or-suffer spells. The saving throw/save DC system was biased in your favor. Some feats, like Spell Focus, were amazing. (Spell Focus [Transmutation], for instance, gave you a bonus to save DCs on spells that could target two saves, making it more valuable than Spell Focus [Enchantment].)
2) Powerful defenses that you could take away many opponents' advantages. Facing a giant, or a fighter? They have a hard time targeting you without True Seeing.
2a) And some very weak defenses. Protection from Spells was lamesauce. By the time you could cast it, your Cloak of Protection was giving you half that bonus anyway.
And weaknesses...
1) Very low hit points and weak saves.
2) You ran out of spells. Ceased being a big issue in the mid-levels. (By this point, your cleric's spell capacity was more important, IME.)
3) Unreliability. While you could steamroll most opponents, some could steamroll
you. Or just roll lucky on their saves. Or you didn't pick the right spells.
Contrast to the fighter, who was reliable... but often reliably weak. The fighter especially had few options. Usually you were just deciding on how much to Power Attack. The feats were weak and didn't scale. Your best feat, Greater Weapon Specialization, gave you +4 to hit. Wooh! (At least barbarians had cool extras, like a significant bonus to their Will save.)
You had no good saves, just a decent Fortitude save, leaving you extremely vulnerable to a wizard's offense (other than direct damage, of course, which bounced off your inflated hit points). Your AC was worthless; very few wizard spells targeted AC (Mordenkainen's Sword and, indirectly, summon spells are the only ones that come to mind). Indeed, physical monsters couldn't miss you either. Hope your cleric is quick with the healing spells.
If an enemy mage used just two spells (Fly and Greater Invisibility), you couldn't reliably target them, you took a 50% miss chance even if you could guess, and you were using a weapon you didn't spend a whole lot of feats on anyway. You could of course spend money on Goggles of True Seeing, but those were expensive and took away from the Christmas tree of items you needed to boost your AC.
In 4e, the classes are actually pretty balanced with each other. At least in my low-level experience, wizards are probably a little weak. They shine in some areas (control, AoE damage) and are weak in others (single-target damage). But they usually have low ACs with little to make up for that. Wizards also don't get the overly awesome defensive spells they got in 3.x, and these spells usually only give you a one-time bonus (for instance, Shield gives you +4 AC, either against a single attack or until the end of your next turn). Spells that let you bypass a fighter's attack roll (eg Displacement) have been rewritten so they merely give you a bonus. Your best bet is to stick next to the fighter and let him use his defender abilities to protect him, rather than staying far away. Let him take the hits; not only is he tougher, but his abilities are actually geared to protecting other PCs, rather than only acting as a roadblock for less mobile enemies like he was in 3.x.
