Cost Mechanic

Sound great.
As you mentioned there must of course be a limit to how much you can "borrow" from the pot. Otherwise the last move a player does when in range of winning is "borrowing" 1000 coins from the pot and make 100 actions, thereby winning the game before the others have a chance to do anything (they´re just sitting there with surprised faces and 1000 coins).

It seems you'd be helping others a lot. After all, you get only 5 coins and all others get times as much (20 coins against in a 5 players game). I foresee the dead-beat feeding all others (much like a runaway looser!). Unless you plan a game about foreign debt in third world countries, it looks unbalancing.

Alternative:
I say that if you run out of coins, you could "sell" your action card to the pot. That means you could get a lot of coins for discarding a high value card, but you'll be loosing a high value card. This way you can also deal with high value cards appearing too early in the game (thus unplayable) or weak cards in late game (thus unuseful).

Keep thinking!

I don't think Louard was talking about borrowing but just taking for free instead. So when you play an expensive action you cannot afford, and give money to the other players, you are not generating debt.

That would just keep the balance among players so that the sum of actions spent + money in hand is the same for all at all times, which is not too different from giving all players X money to buy their actions.

The interesting part of this idea, to me, comes when you limit how much you can use from the pot, but let players spend as much as they want from their hand. Then you have an interesting savings system where the player who's spent less in his actions so far has an advantage proportional to his frugality. If you combine this with some -limited- free actions and a rule like "no drawing from the pot on the last round(s), after some game end condition is triggered", you have a pretty interesting scenario.

. . . About letting players bid on how much they'll take from the bank to let you play your card for free?

(Just popped into my head, and kind of related, and might fix the whole 'I'm giving away 5 times what I spent, which in theory should then get some damage spread around, but might just get pointed back at me by each of them' thing.)

Kind of like taking on your debt, or being a contractor or something.

I'm sleepy.

I think the idea is OK, not knowing ofcourse how it would play out, but when I started reading I felt like it was a real good idea, until you said how coins would be distributed.

My opinion is that this will quite soon equalize the whole coins distribution and that it won't really have a big impact on the game.
You might wanna lower the distribution of the money, and enforce that a "building" that is built with the common gold pot is open for public use, and a building built with your own money is all yours to control.
Or say that money you take out of the pot is actually a lone from the other players in the sense that you have to pay the money back to the other players during the game.

I like the initial idea, but I think it should be a more "cut-troath"