Ring of Force Shield applicability

[Torbyne]

How does this work? "a shield-sized (and shield-shaped) wall of force that stays with the ring and can be wielded by the wearer as if it were a heavy shield (+2 AC). This special creation has no armor check penalty or arcane spell failure chance since it is weightless and encumbrance-free. It can be activated and deactivated at will as a free action."

Does that allow activating at the end of your actions to gain the AC between rounds?

As a force effect it applies against incorporeal attacks but not touch attacks, correct? (not that there are many non touch incorporeal attacks)If you wanted to shield slam with it does it count as ghost touched?

It is weightless and encumbrance free (and presumably just floating in front of your hand) but still a heavy shield, can a charcter use that hand for somantic spells or holding items?

[Nosdarb]

As far as I know, people like to turn it off at the beginning of their turn, use both hands (two-handed weapon or two-weapon fighting), then turn it back on.

Additionally, it shouldn't interfear with spell casting or anything else that uses both hands.

It's a force effect, so you should be able to shield bash with it. It should also affect incorporeal things, much as a magic missile would.

It can't be enchanted (it's not actually a shield), so this all seems perfectly reasonable to me. Your mileage may vary. Check with your GM for details.

[Azoriel]

Unless otherwise stated, free actions can be taken at any point during your action; you should be fine activating the ring at the end of your actions (just so long as it is still your action when you do so).

I, too, treat it as a force effect when used as a weapon. In that regard, it's actually even better than ghost touch because you can use it to whack stuff on the Ethereal plane (assuming you had some way to see said stuff).

To the best of my knowledge, it still occupies a hand while active. (Yes, it is weightless and has no ACP, but shields by default take up your hand, and no exception is given for an active ring of force shield.) Note that this would only happen while the shield effect is up - whenever you deactivate the ring (or if it's deactivated by some external effect), you have free use of your hand again.