Timing conflict with debt card effect

Question

We were playing a game of 7 Wonders with the following expansions: Cities, Leaders, Great Projects (comes as part of the Babel expansion).

At the end of a particular round, we ran in to a conflict in regards to how to resolve effects that occur simultaneously.

1. One player had played a card that forced each player to discard a certain amount of gold (I believe it was related to the number of military victory tokens).

2. The other player built a stage of his wonder (Halicarnassus B) which allowed him to build a building out of the discard pile.

   The building he chose was of the type required by the Great Project. He just needed to pay additional gold to get a participation token.

The conflict was that if he resolved the other players effect first, he wouldn't be able to participate in the great project. If he resolved his effect first, he would just need to take debt tokens.

I went through the rules and couldn't find anything obvious stating how to resolve these kinds of conflicts. Does anyone know how this situation should be handled?

Answer 1

From the Cities rule book (4):

Important: monetary losses are always resolved at the end of a turn, after players have played their cards, possibly having paid for trade and/or obtained money...

The player is able to participate in the project, but he/she would have to take debt afterwards.

As for whether that player has to participate in Great Project if he/she was going to, I haven't found ruling on it. Player consensus is this being optional and that player may make decision on it after they discovered debt threat.

Answer 2

I will add a precision : you can always choose to take debt instead of paying.

From the Cities rule book, an example:

Tina has the required coins but decides to keep them for later in the game: she therefore takes 2 Debt tokens.

So even without the rule quoted by Deo, player is free to participate or not.