Oracle is to Cleric as Sorcerer is to Wizard. They are balanced by design and, in my experience, in play. You get to cast on the fly, which is good, but know fewer spells, which is bad. You have additional cool powers to put icing on top. There are plenty of good Oracle builds, but it's impossible to help you without knowing your build or what it is you think your Oracle should be doing - healing, combat, etc.
Pathfinder is different from 3.5 in that "splatbook" classes are not generally more powerful than the core classes. Their specific design goal is not to continually escalate power. They have taken care (in most cases) to not degrade the core classes and to make base classes, alternate classes, prestige classes, and templates balanced with core classes so that, for example, a level 12 fighter is never worse than a level 12 (combination of crazy stuff). There's only one real exception, the ninja is "just plain better" than the rogue. But besides that, the other classes are neither better nor worse, just different.
Thou shalt not sacrifice caster levels.
As the golden rule of 3.5 multiclssing, it's hard to beat the above. It's quite possible to apply requirements gathering methods to 3.5 as well as 4e, and estimate approximate to-hit and damage at each level.
Plan out your character to 20.
To answer:
s there an effective way to identify class combinations which seem appealing up front, but which will fall behind as the characters level up (without actually taking the character through its paces in a game)?
is simple: plan out your character to level 20. Identify, at each level, what benefit the character is deriving from your choices. Test against the requirements given in your requirements step. This way, when your character shows up in game, you have an idea of your intent and the capabilities of the character.
To answer what classes synergize well:
Non primary-casting classes tend to synergize well.
Given that most aspects of a level up are cumulative with prior choices (BAB, feats, HP) you want to avoid class features which depend on your level in the class. Therefore, avoid class features which have level as a variable within the feature.
Rages from barbarian are fine. You get more as you level up:
a barbarian can rage for a number of rounds per day equal to 4 + her Constitution modifier. At each level after 1st, she can rage for 2 additional rounds.
but you don't have the benefits of the rage reduced (proportionally to your compatriots) as you see in spells.
For the casting classes it's certainly possible to combine them in "gishy" characters (spell-slinging fighters) but they require a specific focus into the combination, preferably enabled by appropriate choice of prestige classes.
So, if you fail to raise rogue, you don't get as much sneak attack bonus damage, but if you're increasing fighter as the other class, you get a higher BAB to compensate.
Whereas a rogue would effectively be writing off "improved uncanny dodge" due to multiclassing.
Therefore, a good combination can be fighter/rogue, because each class brings a separate thing to the table, without having a significant opportunity cost for choosing the other. Other good combinations are those that lead up to exceptional PrCs, which combine features from both classes in useful synergy.
Best Answer
No, damage reduction still applies
What they are referring to is the fact that precision damage now affects constructs, plants, and undead creatures now; in 3.5 those types were immune. In Pathfinder, only elementals and oozes are immune to precision damage.
Precision damage is of the same type as the attack to which it is applied. The only exception to this that I am aware of is attacks that deal ability damage or drain, or energy drain. In 3.5, precision damage that triggered on such attacks was dealt as Negative Energy damage. I don’t know if Pathfinder has explicitly addressed that case, but for sanity’s sake I strongly recommend all DM’s use that rule or something like it.
For the sake of citation, the rules say the following:
That is, Sneak Attack provides a bonus to your damage roll. As a bonus to a roll, it’s just a number that gets added on to your overall damage. It does not change the attack’s damage type, it simply increases the amount of damage of that type that you do. The term “precision damage” is not a damage type, like “slashing damage,” but rather a category that certain sorts of damage bonuses go in. In this manner, it is similar to non-lethal damage.
Note: The statement that Sneak Attack may be used more frequently is perhaps misleading
That’s not really the effect that Pathfinder’s changes had: they allow Sneak Attack to be used more broadly, but there are a number of changes in Pathfinder that make it much more difficult to accomplish multiple Sneak Attacks in one round. Unfortunately, the rogue needs to do so if he is to pose much combat threat, so this is a serious problem.