When to not Take 10 on Knowledge checks

[Ogadim]

My Bard will soon be hitting level 7 (6 in Bard with 1 in Oracle). Since I took the Lore Mystery for my Oracle splash, I have access to the revelation Lore Keeper (use CHA modifier in place of INT modifier for Knowledge skill checks). This revelation combined with my Bardic Knowledge bonus, Circlet of Persuasion bonus, and Headband of Alluring Charisma +2 give me a base of +15 to a Knowledge check in which I have only a single rank invested (+5 CHA, +1 rank, +3 class skill bonus, +3 Circlet of Persuasion bonus, +3 Bardic Knowledge bonus).

When coupled with the Bard class ability Lore Master, I can Take 10 resulting in at least 25 for any Knowledge skill in which I have a rank invested. My question is this: under what circumstances would I need to make a check of greater than 25 DC requiring a roll?

[Mortag1981]

It really depends on your GM. Me personally, I have no problem telling my players what the DC is, but some GMs may want you to decide to roll or not before giving that out.

As a general rule though, you tend to find out more with a higher roll, so unless it's a quick one answer question, I would almost always roll the die. Even if you get a 2 you're still hitting 17 on any roll.

Also, things dealing with Gods, Ancient Badness, Esoteric Lore, etc. will probably have higher DCs, so you can safely assume you should roll those. I'd also roll anything to do with magic items, as cursed items add to the DC to realize their cursed I believe.

[Cevah]

PRD wrote:

You can use this skill to identify monsters and their special powers or vulnerabilities. In general, the DC of such a check equals 10 + the monster’s CR. For common monsters, such as goblins, the DC of this check equals 5 + the monster’s CR. For particularly rare monsters, such as the tarrasque, the DC of this check equals 15 + the monster’s CR, or more. A successful check allows you to remember a bit of useful information about that monster. For every 5 points by which your check result exceeds the DC, you recall another piece of useful information. Many of the Knowledge skills have specific uses as noted on Table 4–6.

Table 4–6: Knowledge Skill DCs <modified excerpt>
Skill DC Task Knowledge
Arcana 15 + SL --- Identify auras while using detect magic
Arcana 20 + SL --- Identify a spell effect that is in place
Arcana 20 + SL --- Identify materials manufactured by magic
Arcana 25 + SL --- Identify a spell that just targeted you
Dungeon. 15 + hazard’s CR --- Identify underground hazard
Nature 15 + hazard’s CR --- Identify natural hazard
Varies 10 + monster’s CR --- Identify a monster’s abilities and weaknesses

I removed all the DC 25 or less entries. I also bolded the part that is really important in combat: know the enemy.

/cevah