Summoner: Does a synthesist (page 80) keep any armor bonuses or other benefits from his armor when he is fused with his eidolon?
No. The eidolon is, in effect, the synthesist's armor, and any armor the synthesist wears does not function while the eidolon is present. Fortunately, this doesn't mean the synthesist has to remove his armor when wearing the eidolon, and when the eidolon is banished/dismissed/killed, the summoner's worn armor immediately begins functioning again.
The Summoner Synthesist is a class that has vexed many and it seems to still be doing it. However I decided to asks a simple question.
If I (a summoner synthesist) call forth my Eidolon, while I'm just wearing normal clothing. Then as a merged form we put on some armor does the combined form gain a AC Bonus (assuming we apply the normal eidolon AC to Natural AC).
The above quote is the answer to the inverse of this question, and follows the rule for Link (which basicly says that a Eidolon and its summoner share magic item slots).
Could it be said that the Eidolon and Summoner share all Equipment Slots, magic or mundane?
Some say that the Eidolon with the Synthesist is a set of Armor, but I disagree, when it is Large sized and looks like a ghostly creature, why can't it be wearing armor.
Just food for thought, anyone who might show some answer to this perplexing question I would love to here you view points.
Many have the issue with imagining that he Synthesist reaches inside of his body to get spell components. What if mind you the Synthesist just put the gear on like normal over top of his Eidolon. Sure it makes him a little weaker, but boy the visuals stop disturbing me.
Eidolons cant wear armor:
Armor Bonus: The number noted here is the eidolon's base total armor bonus. This bonus may be split between an armor bonus and a natural armor bonus, as decided by the summoner. This number is modified by the eidolon's base form and some options available through its evolution pool. An eidolon cannot wear armor of any kind, as the armor interferes with the summoner's connection to the eidolon.
Also in regards to magic item slots they already do share them:
Link (Ex): A summoner and his eidolon share a mental link allows for communication across any distance (as long as they are on the same plane). This communication is a free action, allowing the summoner to give orders to his eidolon at any time. In addition, magic items interfere with the summoner's connection to his eidolon. As a result, the summoner and his eidolon share magic item slots. For example, if the summoner is wearing a ring, his eidolon can wear no more than one ring. In case of a conflict, the items worn by the summoner remain active, and those used by the eidolon become dormant. The eidolon must possess the appropriate appendages to utilize a magic item.
Eidolons can not wear armor. Just because you happen to be wearing your armor, doesn't mean it can.
If you really want armor for your eidolon, mage armor works.
mage armor is a great answer, and probably works far better. However I've put this case up because the logic with the synthesist is flawed. Communication between the Summoner and the Eidolon is not hampered because the Eidolon is surrounding the Summoner, in constant contact. The armor is on the outside of the Eidolon.
The argument that armor interferes for non synthesist is perfectly fine. Call it nature of the magics. But how visually does it interfere when it is in constant contact with the summoner?
I can accept play-test have said it is too powerful. However the in game explanation for the balance does not hold any merit when applied to the synthesist.
Part of the job of Running a game is to try and make the setting have some sense of understanding.
If I as a GM say you may not armor your Eidolon because the magic you use to control it is interfered with by the armor, the armor is between you and the Eidolon. Then another player whom is playing a synthesist says so why is it that I can't put armor on our fused form. My answer cannot be the same. However it must be.
I can rule that with a Synthesist you can wear armor however if it dies or is banished the armor falls upon you and is too large, so you will take armor check penalties regardless of proficiency, well a player could understand that. I could rule that the any items that the fused for uses external falls to the ground all about you if it is killed or banished and you need to make a reflex save of DC 15 or be tripped by your on gear. I think is something a character could understand.
We are already asked to throw out economic systems. Is it so much to ask that the fictional magics make some basic fictional sense?