The cost to play a project card must be paid with MC. You can use MC cubes you have and/or discard other project cards in your hand at a rate of 3 MC per card. Any overpayment in cards is returned to you using cubes. (Ex. You can play an 8 MC card by discarding two cards and paying 2 MC, or by discarding three cards in hand. If you discard the three cards, you will receive 1 MC back.)
Some cards have additional requirements in order to play them. Cards with requirements have a checkmark icon () next to the cost of the card. These requirements are listed in the text box at the bottom of the card next to the same checkmark icon () and shown in icons at the top. If a card has an ocean, oxygen, or temperature requirement, that requirement needs to have been met at the start of the phase in order for you to be able to play it. If the requirements of a card are not met, you cannot play that card.
The cost of Project cards with a building tag (), regardless of color, is reduced by 2 MC for each steel you have. The cost of Project cards with a space tag (), regardless of color, is reduced by 3 MC for each titanium you have. The cost to play a card cannot be reduced below zero.
You may play cards that raise parameters beyond their maximums or add special resources when you don’t have a card to add them to. You will simply not receive the benefits of those effects.
Example: Bob wants to play Microprocessors, which is a green card that costs 17 MC. Microprocessors has a building tag (icon). 1 Bob has two steel, so his cost to play cards with building tags is reduced by 4 MC. 2 Bob chose the development phase this turn, so his cost to play this green card is reduced by 3 MC. Thus, Bob’s cost to play Microprocessors is 17-4-3=10.
3 Bob has 4 MC cubes which he can use to pay for the card, but that leaves Bob 6 MC short of playing it. Bob can discard two project cards from his hand at a rate of 3 MC each to pay for the remaining 6 MC. 4 Bob chooses to discard two cards and spends his 4 MC cubes, and places Microprocessors into play.
5 Bob resolves the immediate effect of the card which is “Draw two cards. Then, discard a card.” Finally, Bob is done with the development phase.
Tip to save table space: Play green cards along the bottom of your player board on the right side. You can overlap them so that just the production box and tags along the left side are showing. Play blue cards in a row above your green cards. You can overlap them so that just the ability icons and tags along the left side are showing. Play red cards in either row, you can overlap them so just the tags are showing.