In NWN2, I believe True Strike gave a +20 to attack. It all but guaranteed that the next attack would hit, which was useful against targets with obnoxiously high AC. I would make a ****load of True Strike potions and invisibility wands, invis myself, chug the potion, then use an min-maxed intelligence assassin Death Attack with a ridiculous paralysis DC, all but guaranteeing that the target would be paralyzed for 10 minutes.
