Terraforming Mars Ares Expedition: Discovery introduces four new mechanics to base Ares Expedition: awards, milestones, upgraded phase cards, and wild tags.

Awards are end-of-game scoring that are awarded to the player with the most of something. Three awards are drawn at the start of the game so that players know what they will be rewarded for at the end of the game. The player with the most of that item gets 5VP, second place earns 2VP.

Milestones are VP that are granted during the game. They are awarded to the player to first achieve the milestone. Milestones are worth 3 VP when the game is over.

Some new project and corporation cards let players upgrade their phase cards. Each phase card has two different version that players pick from when they upgrade them. The upgrade gives the player a better bonus when they select that phase.

Some of the new project cards have a wild tag. Whenever a player reveals this card either from the deck (due to an effect) or from their hand because they are going to play it, that player picks what tag they want it to be. Tokens are used to keep track of what tag was selected for the rest of the game.