Twilight Cost Question

[admiral_jones]

Can any good possession or condition (or any good card for that matter) assume a twilight cost that is negative? This is probably somewhere in the rules, but I don't remember ever seeing it. Like, if I have three gandalf's wisdom in play and i play a wizard's staff, do I remove one, or do I pay a twilight cost of zero.

[bibfortuna25]

If any value goes below zero, that value gets reset to zero.

Edit: However, all modifications are taken into account when all is said and done. If, say, Forearmed reduces Castamir's strength to -2, and then the Shadow player plays Wind That Sped Ships for +6, then Castamir's strength now becomes 4.