Thankyou Ms. Dowd. If you selectively edit you can make stuff say what you want to say and the selective editing in this case made it appear that I said that a character with a low score and no spell focus could get a 50% chance of effecting opponents on a strong save (which any specialist will regularly have to target). Not likely past level 8. The 50% figure is for a character with a 17+ starting prime stat, the best int or cha enhancing item he can afford, and greater spell focus in the appropriate school. (And apparently, even then it's something of an exaggeration).
Really, there are some monsters that show up at CR 10-12 with saves like +17/+10/+6. A lot of giants (the fire giant has an achilles heel for instance (CR 10, +14/+4+/9 as does the frost giant CR 9 +14/+3/+6), Hydras (at CR 9, +12/+8/+3) and the frost worm are in that category. But a lot more foes are like golems (immune to magic so their saves don't matter much), the hill giant dire weaboar (+17/+8/+12 or +20/+8/+12) the athach with +9/+5/+10 at CR 8 (an consequently much higher if advanced), demons (at CR 20, SR 28 and +22/+19/+19 saves, at CR 13, the Glazebru has SR 21 and +18/+8/+11 saves, the Tyranosaurus (CR 8, +16/+12/+8), dire animals (all good saves; the CR 7 dire bear has +12/+9/+9 and the CR 8 dire tiger has +13/+12/+11), dragons (very good saves all around--CR 13 red dragon is +16/+11/+13 with SR 19), efreeti (CR 8 with +9/+10/+9), Kraken (CR 12, +21/+12/+13), Mohrg (CR 8 and +4 (not that they're vulnerable to much here/+10/+9), night hags (CR 9, SR 21 and +12/+9/+10), nightwing (+9/+11/+17), vampires (lots of resistances, fort save immunity, +4 dex and lightning reflexes, +2 wis)
Overall, the typical level good save for CR 8-12 seems to be +14 or above and the typical non-good save (is +9-+10); if it's as low as +6, it's a really bad "glass-jaw" type save.
So, starting a wizard off with a 14 or 15 int, by 10th level (when he'd be facing monsters throughout that challenge rating), he'd probably have an int of 19 (+2 item, +2 stat increases). Consequently, without spell focus feats, his DCs will range from 15 to 20. That means that his most powerful spells have a 65% chance of working when targetted against a glass-jaw type save, a 45-50% chance of working when targetted against a typical non-good save, and a 25-30% chance of working when targetted against a strong save. (Not forgetting that something like 1/3 of these creatures have SR. . . .) Of course he only has 2 spells (unless he's a specialist) at his highest level castable; the spells he'll spend the bulk of his time working with (3rd and 4th levels) have even less chance of working. (For the 3rd level spell like fireball it's 50% chance against a glass jaw save, 35% chance against a typical save, or 15% chance against a strong save.
So, how about the high int spell focus guy? Starting with an 18 int, and the same items, he has a 22 int at 10th level. With Greater Spell Focus, the DCs for his highest level focussed schools are 23. So, he has an 80% chance of success against the glass jaw save, a 60-65% chance of success against a typical save, and a 45% chance of success against a strong save. That's with his highest level spell. With his fireball spells (whether actual fireballs, Suggestion, Hold Persons, or Rays of Exhaustion), he has a 70% chance against glass jaw saves, a 50-55% chance against normal saves, and a 35% chance against strong saves.
Now, the big difference is that the high-int focussed guy is always in the position of having a reasonable shot at success. The other guy isn't. A 35% chance is still worth taking if it's the best you can do. If your choice is expending a very limited resource (spells) for a 15% chance of accomplishing anything, options like "I throw my dagger to Aid Other on the fighter's attack (or AC)" and "I pull out that clvl 1 wand of magic missiles to do 1d4+1 damage to the critter--it's not much but it's something" start to look really attractive. When the average int wizard comes across the 50-60% of monsters that seem to have no weak saves, he runs the risk of being a glorified commoner.
Of course, there's a big difference when facing the glass-jaw saves too. Mr. Average int, no spell focus has about a 50% chance of success with his bread and butter spells. A 65% chance of success translates into significantly better results. (For instance, if you catch 6 targets in the fireball, it's the difference between 3 targets failing the save and 2 targets failing the save--the amount of extra damage from that 15% adds up pretty quickly).
Li Shenron said:
I have nothing left to say, we clearly have a different concept of "slim chance".