In the end off book rules, there is "players actions" frameworks.

My doubt is, for example, I have the card "Our most desperate hour" - Action: Place a shield on a target Character unit . - OK ,

I Can use this card in ANY time of the play actions framework? In final Force phase, there is a player action, may be it is an 'illogical moment' I can use even if not on my turn that kind of card?

Thank you

Events can be used at any time allowed by the timing (Action, Reaction, Interrupt) printed on the card.

For Actions : they can be used in any Action window (see the flow chart in the back of the rulebook for complete listing of action windows).

For Reactions : they can be used immediately following their triggering condition (general timing for Reactions).

For Interrupts : they can be used once their triggering condition has initiated, but before it finishes resolving (general timing for Interrupts).

Events can be used on either player's turn.

So in you specific example, you could indeed use Our Most Desperate Hour during any Action window (remembering that Actions pass back and forth between players in each Action window, starting with whose turn it is). Using it in your opponent's Force Phase is likely pointless, but you are allowed to do it.

Thanks dbmeboy, very helpful.

The general rule to understanding cards:

-Know the timing rules well

-Cards do what they say they do

-Cards don't do what they don't say they do

-Don't bring in assumptions from other games you might play

-Feel free to ask questions when you're not sure, there's plenty of us who stalk the forums to help out with rules questions.