Cards costs and empowering

All cards are free to place into the void. However, when they resolve, certain costs and requirements must be adhered to if present on the card.

Empower is an attribute that allows a resolving card to be boosted. To empower a card, one or more element tokens can be placed onto the card. This may increase the damage of a spell, or increase the strength of a warrior as it enters play.

Sacrifice allows existing creatures to be killed in order to boost a resolving card. For example, a summoning ritual may allow stronger elementals to come into play if creatures are sacrificed to boost the ritual.

Replace requires a certain card to already be in play. If a suitable card is available to replace, that card is spent. For an example, an existing village is required in order to play a town or an occupied village. Some replace cards override the spent effect of the replaced card. In the above examples, a town card may return a village card to its owners hand if it is empowered.