Can a resource card be used more than once in a turn when allowed to build more than one structure?

Question

Scenario:

• Player is using Babylon (side B)
• 2nd wonder has been completed (allows playing last card of each age instead of discarding)
• Player has a Mine in play (can produce either Stone or Ore)
• Player has no other way to produce Stone or Ore and no money to purchase from a neighbor
• It is the 6th turn of Age I
• Player has a Barracks and a Baths in hand (resource cost of one Ore and one Stone, respectively)

Can the player play both Barracks and Baths?

The 2nd wonder allows the player to play both the Barracks and Baths (assuming he can pay the costs), instead of having to discard one. The Mine can produce both resources, but the rules regarding cards that can produce more than one type of resource state:

the player can use one OR the other resource to build a structure (or a wonder phase) but NOT both in a given turn.

Both cards would be played in the 6th turn, so it would seem that the player cannot use the Mine to pay the cost of each card. However, is the limitation on using resource cards only once per turn really meant to be once per construction?

This question really applies to any resource producing card, not just the multi-resource producing cards. It was just simpler to explain this way, and the issue is more fuzzy due to the specific prohibition on multi-resouce producing cards being used more than once in a turn.

Answer 1

The consensus opinion, based on asking the games' creators how situations such as these were intended to be resolved (see this BGG thread), is that you should treat Babylon's "play last card of each age" power as, in effect, a 7th and separate turn. If you do, then naturally you would be able to use your resources once per build, not have to divide them between the last two cards.

I think this is definitely the way to go, just for pragmatic reasons: Babylon's power seems pretty poor if you have to pay for your last two cards in an Age with one set of resources. It's hard enough to buy one card with the resources available in the final stages of the game - buying two at once would be an almost impossible feat!

Answer 2

The gamer designer (Antoine Bauza) answered a similar question:

When playing both cards in round 6 to build two buildings: Can you use one resource twice for each of the buildings?

Yes, it's two different cards, like two different turns... The first could help you to play the second (discard the 6th for money and use the money to play the 7th for example...)

(found by user1873, who posted it in an answer to a duplicate question)

So there is no actual 7th turn, but the commerce and building rules work like there would be one. This means, for example:

• You can build the relevant 2nd wonder stage in the 6th turn, and then make use of your last card.
• You can build a resource card in the 6th turn, and use it to build the last card (same if a neighbour builds it).
• You can earn money in the 6th turn, and use it to build the last card.
• You can use the same resource card (and for resource cards that let you choose, make different choices) for building your last two cards.
• If your neighbours benefit from played cards or built wonder stages (thanks to a card they played in the 6th turn), they only benefit from your 6th card, not from your 7th card (… I assume).
• If a player may go through the discard pile (e.g., thanks to Halicarnassus), and you discard your last card for money, this card gets added to the discard pile before the player goes through it.