1) You can hold extra things in the hand, you can spellcast with it, you can retrieve items, you can have a free hand to do anything that isn't an extra attack.
2) Will. Saves against bardic performances are will saves.
This brief description summarizes what occurs when a bard performs the masterpiece. Unless otherwise stated, a masterpiece's effects are supernatural. Unwilling creatures may attempt a Will save against the effect of a masterpiece; the save DC for masterpieces is equal to 10 + 1/2 the bard's level + the bard's Charisma bonus. Masterpieces that duplicate spells use the bard's caster level for the spell's caster level.
but wouldnt that retrieving items, spellcasting and so on afford another action? (swift/standard/etc) which you don't get.
You wouldn't get another action from it. It would mean that you could do things like fight with two weapons while holding a shield with a third, or hold a weapon, a shield and cast or drink extracts.
but wouldnt that retrieving items, spellcasting and so on afford another action? (swift/standard/etc) which you don't get.
It's true you don't get extra actions, but you could for instance be holding a two-handed weapon and use your 3rd arm to retrieve an item without needing to drop your sword.
It's a level 2 ability that is useful, it's just not extra attack or action useful (which would be game breaking).
For full reference please see the following FAQ:
Alchemist, Tentacle/Vestigial Arm: What does "extra attacks" mean for these discoveries?
It means "extra," as in "more than you would be able to make if you didn't have that discovery."
For example, if you're low-level alchemist who uses two-weapon fighting, you can normally make two attacks per round (one with each weapon). If you take the tentacle discovery, on your turn you can make
* two weapon attacks but no tentacle attack,
* a weapon attack with your left hand plus a secondary tentacle attack, or
* a weapon attack with your right hand plus a secondary tentacle attack.
At no time can you make a left hand weapon attack, a right hand weapon attack, and a tentacle attack on the same turn because the tentacle discovery says it "does not give the alchemist any extra attacks or actions per round." This language is calling out that the tentacle is not a standard natural weapon and doesn't follow the standard rules for using natural weapons (which would normally allow you to make the natural weapon attack in addition to your other attacks).Likewise, if you instead took the vestigial arm discovery and put a weapon in that arm's hand, on your turn you can make
* a weapon attack with your left hand and one with your right hand,
* a weapon attack with your right hand and one with your vestigial arm, or
* a weapon attack with your left hand and one with your vestigial arm,
At no time can you make a left hand weapon attack, a right hand weapon attack, and a vestigial hand weapon attack on the same turn because the vestigial arm discovery says it "does not give the alchemist any extra attacks or actions per round."
The exact same restrictions would apply if your race had claws or you had some other ability to add claws to your limbs: the text of both discoveries says they do not give you any extra attacks per round, whether used as natural weapons, wielding manufactured weapons, or adding natural weapons to a limb that didn't originally have natural weapons.Remember that these two discoveries do not have any level requirements, and therefore are not especially powerful; permanently adding additional attacks per round is beyond the scope of a discovery available to 2nd-level alchemists.
ah, ok. Thx.
One further question i bother with: Can I detect a spell caster with detect magic or just the spells he or she has casted?
In this case the spell caster is a normal human magician (or likewise)
I think the spell discription doesn't say so.
Detect Magic doesn't detect magical creatures. It detects magical auras, which are not innately made by magical creatures (unless a specific ability says otherwise). A mage wouldn't appear to be the slightest bit magical unless they had magic items on them or had cast a spell on themselves.
an age of "i see if there are any spellcasters nearby by casting detect magic" comes to an end :)
Thank you.
Not quite, if they are casting magic you will detect them.
And if they are wearing magical items you will detect them.
If they have magical effects on-going on them, like mage armor (almost all wizards do), you will detect them.
Just because a creature can use magic, doesn't allow you to detect them. But casting, have a spell effect with active duration on you, or having magic items on your person will all set off detect magic.
an age of "i see if there are any spellcasters nearby by casting detect magic" comes to an end :)
Thank you.
You want the spell Arcane Sight, which will tell you the highest level spell a caster currently has access to, and if he is an arcane of divine caster.