When using a card with the variable "X" on it, the value of X is set by performing the effect X is listed in when it is necessary to resolve that effect. X is bound by any limiting factors relevant to the effect setting the value of X.
When is a variable chosen for a card in which that variable is not defined by the card itself?
OPTION ONE: To me, the answer is very clearly that X is decided the first time card text with X resolves, which makes all of the named cards make perfect sense.
- Vamp: X is chosen when the run is successful if the runner chooses to use the instead-of-access effect by the runner spending X credits.
- Atman: X is chosen after Atman is installed by spending X credits.
- Corporate Troubleshooter: X is chosen by spending X credits as the cost to activate the paid ability.
- Power Shutdown: X is chosen after playing the event by trashing X cards from R&D.
- Psychographics: X is chosen while playing the event by paying X credits as the play cost.
- Dracō: X is chosen after Dracō is rezzed by spending X credits.
OPTION TWO: However, there are some people who believe that variables would function more like in Magic, wherein the value of X is decided by the player when the card is played/activated, and then the effect is resolved pretending that all X's are replaced with that chosen value. I'm not sure all of the cards make sense if this is the case.
- Vamp: X is chosen when the event is played. The runner has to guess how many credits s/he will have to spare by the time the run is successful. When the run becomes successful, the runner now has to decide between accessing cards or spending the number of credits s/he arbitrarily chose at the beginning of the action, which may or may not be possible anymore.
- Atman: X is chosen when Atman is installed. This functions fairly identical to the other option, with the weird exception that I could choose to either set X as 0 to pay 0 credits to put 0 power counters on Atman or I could choose X to be 5 billion and pay 0 credits to put 0 power counters on Atman because I can't pay 5 billion credits. I could even choose X to be a number of credits I can afford but then decline to pay because of the "may" to put 0 power counters on Atman.
- Corporate Troubleshooter: This is tricker. If I choose X when I install the card, then the card is very obviously Corporate Troubleshooter because I have to tell the runner "Click two: install a card in this remote and set X to 12". If I choose X when I rez the card, then it still functions fairly well, I just can't rez it ahead of time and expect it to be useful, and being forced to rez it is really bad for me. If I choose X when I activate the paid ability, then the card works as what is seemingly intended because I can't activate a paid ability that I can't pay for, so I couldn't arbitrarily choose 5 billion and make the ice impenetrable without paying the credits.
- Power Shutdown: This card is a little weird if I choose X when I play the card. I could theoretically choose a number higher than the number of cards in R&D and then trash less cards than the runner has to trash in cost of program/hardware.
- Psychographics: This card is the only one that makes perfect sense in this scenario because the cost of the card is the X, which has to be decided when the card is played anyway.
- Dracō: This card has all the weirdness of Atman and Corporate Troubleshooter combined.
The biggest issues here are Vamp, Corporate Troubleshooter, and Power Shutdown. So which is it? Option One or Option Two? Or some other option that I haven't thought of yet?
If the answer is Option One, then there is a follow-up question: When deciding X, is it decided by the effect including X or is it decided by choosing an X and then resolving the effect with X in it? For example:
- I play Vamp. I run on HQ. The run is successful. I choose to use the instead-of-access effect. I spend 1 credit at a time until I am satisfied with the value of X. The corp is forced to lose up to X credits.
- I play Vamp. I run on HQ. The run is successful. I decide that X is 5. I may then spend 5 credits to force the corp to lose up to 5 credits. This allows me to choose 5 credits when I only have 3 in my credit pool, which gives me a successful run without having to access cards (if I know they have a bunch of or whatever). s
This follow up question is pretty important in regards to Power Shutdown because it makes the difference between (a) trashing cards one at a time until I decide X is big enough for whatever reason, whether I reached my target X or I saw too many agendas go into archives and I want to stop, and (b) declaring the number of cards I will trash, agendas be damned.