On the comments of Clogged with Corpses, we learned that costs of 0 cannot be paid: http://www.cardgamed...omment_id=50766
We also learned that cards with cost 0 actually mean "this card has no cost" rather than "there is a cost and it is 0."
If I use Sae'lum Enclave which reads "Interrupt: When you deploy a non-Tau unit, exhaust this support to reduce that unit's cost by 2." to reduce the cost of 10th Company Scout to 0, am I allowed to pay the 0, or am I not allowed to pay the 0, or does reducing 1 to 0 in this way somehow remove the cost rather than reducing it?
If I have a Valkyris Pattern Jump Pack in reserve at a planet, which reads "Deep Strike (0). (Deploy this card facedown for 1 resource. When a battle begins, you may pay this card's Deep Strike value to turn it faceup.)", does that actually mean there's no cost, or that I must pay 0, in which case I could not deep strike it?
If the card has no cost to deep strike it, does that mean I can still deep strike it without paying any cost if my opponent has a Catachan Tracker at the planet, which reads "Increase the Deep Strike value of each card your opponent controls at this planet by 2."?