Hello,

Looking at cards such as Daemonslayer (Dwarfs),  it has an action that reads "Action - When you play a development from your hand put a resource token on this card".   Now, if I have two copies of that card in play and I play a development will I trigger the action on both of those cards by meeting the single trigger condition? As I understand it there is no limit to the number of times that a card can repeat it's action (as long as I can pay the cost obviously), but in the situation above, it would be two cards triggering off of one trigger condition. I play the development and trigger the action on one card. Has that window of opportunity  to trigger again on the other copy of the card been lost?

Cheers

Yes, you can. A trigger condition isn't a cost. When it is met, all effects that have that trigger condition can (or have to, if they aren't optional actions) be triggered. So if you have multiple cards with "Action: At the beginning of your turn …" or multiple cards with "Action: When you play a development …" or some other shared trigger condition, they can all be triggered once the condition has been met. 

 So, multiple actions may be taken during each action window?

Of course. Each player can take an unlimited amount of actions during any action window. As long as he has legal targets for the actions, can pay the cost, and fulfill any other requirements. Any single action can be triggered an unlimited amount of times too, with the same provisions. Any single triggered action though can only be triggered if the trigger condition was met and only once per trigger condition met.

Mallumo said:

It is this specific aspect that I wondered about, because in the example I gave the trigger condition has been met once (a development card played) and an action has been triggered twice by two cards (place a resource token).

Yes, but they are different actions. Daemonslayer A has an action, and Daemonslayer B has an action, both have the same trigger. They are independent of each other, you can trigger both, just one, or neither of the two, as long as you trigger any single one of them only once. That they happen to have the same effect doesn't matter. If you trigger the actions on two Sorcerers of Tzeentch, you deal damage two times and not one combined amount of damage from both, because they are separate, independent actions.