Prerequisites, when are they fulfilled?

[Bloodgruve]

As you level, when does a prerequisite count as being fulfilled?

For instance, Skill Trick; Collector of Stories requires 5 ranks in a knowledge skill. Can you take this at level 2 after you assign a skill point in a knowledge to take you to 5 ranks or must you have the prerequisite fulfilled during the previous level?

Same with Feats, can you take Arcane Strike which has a prerequisite of +6BAB as you hit 6th level in say Duskblade?

Obviously prerequisites for PrC's must be fulfulled prior to entry into the class.

TYVM

Blood~

[zanetheinsane]

Not sure about the others, but as for the feats, under page 58 of the Player's Handbook, raising your Base Attack Bonus is the second step of the Level Advancement procedure, well before selecting feats.

This thread (http://www.giantitp.com/forums/showpost.php?p=12745211&postcount=2) has some good information in it.

[Answerer]

Feat and skill trick can be taken the same level you meet the prerequisites. Prestige classes cannot.

[Bloodgruve]

Very good, thank you for the responses.

Blood~

[DefKab]

Feat and skill trick can be taken the same level you meet the prerequisites. Prestige classes cannot.

To further expound on this, it's because the class gives you the skill points to meet a prerequisite.
For instance, if a particular Prestige Class requires Knowledge Arcana with 8 ranks in it, at 5 level, you'd only have 7. You'd have to pick a class you qualify for, (Like wizard), and that will give you skill points. As you assign them, you'd then have 8 skill ranks in Knowledge Arcana, which meets the prerequisite for the Prestige Class for your sixth level...

[zanetheinsane]

The only tricky part comes when you try to pick a feat (or skill trick) that has a feat prerequisite you get as a class feature. Although rare, you technically could not pick a feat at 3rd level that had a prerequisite feat you received from your 3rd-level class.

Most DMs I know of would absolutely allow this even though RAW you could not do it.

For example, let's say you multiclassed so that at level 3 you were Fighter Level 2. You can't use the bonus feat from fighter to qualify for your 3rd level feat since it's technically a "class feature" and acquiring class features are the last step in level advancement (PH p59).