Lets say you rolled a total of 6 advantages. Would you be able to purchase an advantage that cost two advantage points three times?

Example

I rolled 6 advantages, and adding one boost die to my next skill check will cost 2 advantage points. I will select that option three times so that I will have 3 boost die added to my next skill check.

Or do you only get to pick an option once unless it says so. (Like recovering strain?)

Yes and...

As the GM I would ask you to build a narrative to describe how you expect 6 advantage would translate to 3 boost dice. Mainly because 3 boost dice is hard to get in a narrative.

For example: I shoot the bad guy and he takes 6 wounds. With my advantage I think maybe the shot bounces off the far wall and hits the walkway he is on, this collapses and drops him to the ground and he ends up prone and in the open. I would accept that, as you use 2 advantage to collapse the walkway and have the bad guy fall down, 2 to have him fall prone and 2 advantage to have him fall into the open space in front of the party. As the GM I would probably say that falling off the walkway causes him a setback on his next roll, and the prone in the open will give the next player a pair of boost dice and following players will get a boost as he scrambles to what limited cover he has and gets up.

I believe, with the exception of regaining strain, each option can be chosen once.

I wouldn't give 3 Boost dice simply because I'd find it boring. For mechanic effects, I might downgrade/reduce difficulty, remove setbacks, or do something else depending on the narrative description provided by the players. If the players wanted a better benefit than 2 Boost dice (and they would be within their rights; 6 Adv is a big deal), I'd tell them/help them to get creative

RAW, you can only grant 2 Boost dice (one "to the next PC," and another "to the PC of your choice").

So yeah, I would only allow a "standard option" like that once, unless it's Strain recovery which is called out as 1-for-1 with no upper limit.

Yes and...

As the GM I would ask you to build a narrative to describe how you expect 6 advantage would translate to 3 boost dice. Mainly because 3 boost dice is hard to get in a narrative.

For example: I shoot the bad guy and he takes 6 wounds. With my advantage I think maybe the shot bounces off the far wall and hits the walkway he is on, this collapses and drops him to the ground and he ends up prone and in the open. I would accept that, as you use 2 advantage to collapse the walkway and have the bad guy fall down, 2 to have him fall prone and 2 advantage to have him fall into the open space in front of the party. As the GM I would probably say that falling off the walkway causes him a setback on his next roll, and the prone in the open will give the next player a pair of boost dice and following players will get a boost as he scrambles to what limited cover he has and gets up.

You know if my players came up with that narrative I would be very happy to try build on it and try and make it more awesome.

Rules or no, making less awesome doesn't seem like the right way to go to me.

Yes, the GM and group can always choose to ignore rules if it gets in the way of fun and the story, but strictly by the rules as written you can choose each table option only once other than strain*.

BTW, being prone makes him harder to hit with a ranged attack (I can't remember if being engaged negates that and turns it into a boost or not).

* Just in case it's not clear, you can choose critical hit and some weapon qualities multiple times, but they have clear rules on what happens each time you choose them. For example, if you roll enough advantages to crit twice, you don't roll on the table twice, you roll once and add +10 per each other time you chose to critically hit

* Just in case it's not clear, you can choose critical hit and some weapon qualities multiple times, but they have clear rules on what happens each time you choose them. For example, if you roll enough advantages to crit twice, you don't roll on the table twice, you roll once and add +10 per each other time you chose to critically hit

How does two crits work against minions? Do you kill two?

* Just in case it's not clear, you can choose critical hit and some weapon qualities multiple times, but they have clear rules on what happens each time you choose them. For example, if you roll enough advantages to crit twice, you don't roll on the table twice, you roll once and add +10 per each other time you chose to critically hit

How does two crits work against minions? Do you kill two?

If you're talking 2 Triumphs or like 6 Advantage, then yeah.

If you're talking 2 Advantage on a lightsaber swing or jury-rigged vibrosword...meh. Maybe. I'd probably tell you that the crit takes down one, and find something else to do with the other Advantage.