To my mind at least, wizards are not supposed to be able to deal out as large amounts of damage to single opponents as melee fighter, this ability is the melee fighter's main (maybe only) strength
Would that be aside from having roughly double as many hit points, a significantly better AC, an incredible number of feats; not to mention the better usage of 'strategic' melee (grappling etc.)
Which is a CR 13 monster. Recall that it was the phenomenon of casters taking down monsters of higher CR than their level in one shot, that caused so much heartache
Granted, but then you can't get a 9th level lich, so that's a non-argument

. With regard to CR 11 monsters, a lot of them have far more hit points than liches, not to mention better Fort saves. Indeed, for purposes of being vulnerable to disintegrate, liches are about the single weakest creatures in the game- hardly representative...
Greater Spell Focus bumps that up to 23. Spellcasting Prodigy bumps it up to 24. Various boom-spell PrCs can bump it even higher
None of which are core rules. 'Backwards-compatibility' is all very well, but if it means disempowering core rules just in case people slap on supplements, then that's clearly a faulty approach.
A wizard with Dex 13 will be dead long before reaching 11th level, for desperate lack of AC. Try Dex 16 at minimum. Add Weapon Focus (ray) and Point-Blank Shot for extra fun
13 Dex is fairly standard. Remember that you'll want a good Con, and a good Int as well. As for WF (ray) and PBS, I've never seen any PC wizard take either.
Ah, this must be an example of the post-modernist statistics they keep telling me about
Well, it was worth a shot

. Seriously though, for the wizard to kill the lich, he must hit (50%), it fail its save (80%) and then roll more than 72 on 31d6 (er...can't be bothered to work out...probably about 90%). So his top spell is only having a 36% chance to knock out the lich, the monster which is weakest against disintegrate. Against creatures with good touch ACs, good Fort saves and lots of HPs, his chances drop dramatically.
The AoO does not prevent the coup de grace.
Bull Rush. Trip. Disarm (okay, so he could do a unarmed cdg, provoking yet another AoO and probably not being very effective unless his Str is exorbitant). Sunder (likewise). Grapple (if he misses on *his* AoO). Think outside the box

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Given how slowly melee tanks move, that enemies can form defensive lines around the held victim, that cdg provoke an AoO and that hold could wear off over a couple of rounds, the PCs' need to be very well-coordinated to do the old hold/cdg trick. I'm not saying that that's *bad* necessarily- I broadly agreed with the hold nerf: it's merely symptomatic of a wider trend.
A wizard going around on by himself, without tanks of his own to guard him, deserves to die. Heck, it happens even in 3E already
Well, are the tanks simply going to sit there and act as meat-shields? Quite often an enemy tank is more than willing to provoke an AoO and charge an enemy mage if he thinks that he can take them down.
If they're as nerfed as you claim, then clearly they're not so dangerous anymore, yes?
Not as dangerous, but still dangerous. Like I said, they have always had, and continue to have, a greater offense:defense ratio than fighters. In 3e, they had better offense and weaker defense; in 3.5e, it looks like they might have comparable offense and weaker defense. Given two targets with comparable offensive capabilities, any sensible opponent will target the one easier to kill.
Last time I checked, you don't count armor bonus for touch AC
I thought mage armour, being a force effect, did count- though to be fair, I'm not entirely sure now you mention it.
Actually, I think that the classes whose foci are not combat (that's most classes except fighters and barbarians) are too good at fighting, not the other way around
Nonsense. Ignoring the fact that combat (under core rules) is both the bulk of encounters in any given game and is the font of nearly all XP, the examples we are using are 'combat wizards'. If I played a loremaster with three Skill Foci in Knowledge skills, poor Dex and Con (good Int, Wis and Cha), an armload of divinations and utility spells and still expected him to match in combat, then of course that would be ridiculous. The argument I'm making is that *combat* wizards now cannot compete.