We're looking at AC 51 for this particular encounter. So using your example - even with True Strike - the PC would have less than a 50% chance of landing a blow on it. Keep in mind that would be only a single attack per round, not likely enough to overcome the combined effects of the creature's DR and regeneration. Plus, what are the other 4 party members doing?
Here's the math I've figured out. 18th level fighter facing the encounter (a little higher than the module recommends). Here is the basics without any buffs or situation modifiers:
BAB +18, +5 magic weapon, +9 Strength, +2 Weapon Focus & Greater Weapon Focus, +4 weapon training. +38 to hit. A slightly worse than 50/50 chance.
But that's just one character (perfectly optimized under ideal circumstances) who has a chance. No one else in the party will come close. Forget about the paladin or rogue landing a hit. Spell resistance and awesome saves will shut down the sorcerer and cleric.
Here's the math I've figured out. 18th level fighter facing the encounter (a little higher than the module recommends). Here is the basics without any buffs or situation modifiers:
BAB +18, +5 magic weapon, +9 Strength, +2 Weapon Focus & Greater Weapon Focus, +4 weapon training. +38 to hit. A slightly worse than 50/50 chance.
But that's just one character (perfectly optimized under ideal circumstances) who has a chance. No one else in the party will come close. Forget about the paladin or rogue landing a hit. Spell resistance and awesome saves will shut down the sorcerer and cleric.