
HaraldKlak |

The Magus Black Blade gains skill points in Knowledge Arcana as it progresses. Howeveer, the blade description also states it has senses - it can see and hear. So should it not also have Perception?
What are the skills that a Black Blade posesses and that can be invested with skill ranks?
It only gets knowledge (arcana) skill ranks:
Languages and Skills: A black blade starts with Common as a language. As the black blade increases in Intelligence, it manifests knowledge of languages and arcane lore. Upon reaching an Intelligence of 12, it gains a bonus language of the GM’s choice, and gains 1 rank in Knowledge (arcana). Each time the sword gains a bonus to Intelligence, it gains another language and another rank in Knowledge (arcana).
In the intelligent items rules, having senses doesn't automatically grant it any ranks in the perception skill. While it should be able to make perception rolls, the black blade is going to do so with a terrible wisdom score.
Intelligent items can get skill ranks (+5 ranks to a single skill for 2500 gp), but since the abilities of the black blade is fixed, it isn't a possibility.
Anomander |

The black blade has all skills, just like any character or NPC in pathfinder. The only question is how much is its modifier to the rolls and can it actually use the skills it has. As it has no physical ability scores it cant use any skills that require physical ability scores, but besides from that it just counts like any other character that is only trained in knowledge arcana.
meaning it can take knowledge arcana checks, it can't take other knowledge checks or any other skills that is only usable if trained (like any other character), it can take perception checks (but it will have 0 ranks and an awfull wisdom score, and so on.
i hope this cleared it up.