Earth is an engine building game played over rounds in which each player gets a turn creating their own island with its terrain and flora. The game ends at the end of the round in which a player completes their island of 16 cards in a 4x4 grid.
The game starts with each player choosing an Island, a Climate and an Ecosystem card. The Island card dictates your starting soil, compost size and hand of card. The Climate card has a basic ability to help start your engine. The Ecosystem card is an end game scoring card.
On a player's turn, they must choose a main action: Plant (green), Compost (red), Water (blue) or Grow (yellow). The active player gets to do a more powerful version of the action and the other players will do a less powerful version. Then, all players can activate their cards with abilities matching the main action color.
- Plant (green): Place cards from your hand in your tableau. You must pay the cost of the card with soil. Cards must form a 4x4 grid at the end of the game. When placing a card, it must touch existing cards from your tableau (diagonally or orthogonally). The active player plants 2 cards and the others plant 1 card. After, the active player draws 4 cards and keep 1 and the others draw 1 card. (Drawing cards cannot be undone so, for the active player, planting the second card cannot be undone. For the others, planting cannot be undone)
- Compost: Gain soil and/or draw card from the deck and place them in your compost without looking at them. Each card in your compost scores 1 point the end of the game.
- Water: Place sprouts (cube) on sprout spots on cards in your tableau or gain soil. Each sprout scores 1 point at the end of the game.
- Grow: Place growth pieces or canopies on growth spot on cards in your tableau and/or draw cards to your hand. Each growth piece scores 1 point at the end of the game but the last piece you place when reaching the maximum growth of the card must be a canopy. A card with a canopy scores the growth score on the card instead of 1 point per piece. (Drawing cards cannot be undone)
After the main action, all players activate their cards with matching color. You either activate your Island, your Climate and then your Tableau or you activate your Tableau and then your Island and your Climate. When activating your Tableau, you activate it in order from left to right and top to bottom. You can skip activating abilities. For abilities with a colon (:), you must pay the cost to gain the benefits.
Note that Black abilities are activated when the card is planted in your tableau. Brown abilities are either in-game effects or end game scoring.
The most common in-game abilities are:
- Draw cards from deck (cannot be undone)
- Gain or Pay Growth pieces
- Gain or Pay Sprout pieces
- Gain or Pay Soil
- Compost cards from your hand
- Compost cards from the deck (cannot be undone)
- Discard cards from your compost (cannot be undone)
- Reduce the cost of cards of a certain type (Tree, Herb, Mushroom, Bush) or with certain habitat (Sunny, Wet, Rocky, Cold)
There are other in-game abilities that are less common:
- Draw cards from your compost (cannot be undone)
- Pay part of the cost of a card with your compost, sprout pieces or growth pieces
- Copy the ability of another card
- Plant another card at no cost and draw cards (cannot be undone)
- Prevent the player from choosing a specific main action
- Cards that counts as any type (Tree, Herb, Mushroom, Bush)
Event cards can be played at any time except in the middle of an action or ability. Played event cards are placed in a pile on the player board. Some event cards have negative score and will make the player lose points at the end of the game. The rules are very clear : events do not count for any Fauna and Ecosystem cards, except if explicitly written on the card, with a lightning icon.
At any time except in the middle of an action or ability, players can convert 3 sprouts to 2 soil (but not the other way around). Note that 3 sprouts is 3 points at the end of the game.
Four Fauna cards are selected at random at the start of the game. These are in-game objectives to complete. The first player to complete the objective gets more points. If multiple players complete an objective in the same turn, the active player scores more points and then players are placed in turn order.
The first player to complete its 4x4 Tableau scores a 7 point bonus. If multiple players complete their tableau in the same turn, the active player scores the bonus or the first player in turn order.
Each player has an Ecosystem card and there are 2 randomly selected public Ecosystem cards. Player's ecosystem cards can only be scored by the player that owns it. Public Ecosystem cards are scored by all players.
Flora vs Cards
When a Fauna or an Ecosystem card mention Flora, it means that it applies only to green planted cards (Tree, Herb, Mushroom, Bush) in your tableau. If they mention cards, it means all cards in your tableau and possibly Island and Climate cards.
End Game Scoring
At the end of the game, the following score points:
- Score on cards in your Tableau, on your Island and Climate cards
- Positive and negative score on your Event cards
- Score 1 point per card in your compost
- Score 1 point per sprout piece on cards in your Tableau
- Score 1 point per growth piece on cards in your Tableau. If a card growth height is maxed (it has a canopy), score the points on the card instead
- Score Terrain cards in your Tableau with Brown abilities that score points
- Score your private Ecosystem card
- Score the 2 public Ecosystem cards
- Score points from the Fauna board: for the 4 cards and the bonus for the first to finish its 4x4 Tableau
Beginner, Standard and Advanced Mode
- In Beginner Mode, there are no Ecosystem cards. Also, all players get 10 points per Fauna card objective.
- Standard Mode is what is described above.
- In Advanced Mode, players get more choices of Island, Climate and Ecosystem cards at the start of the game but the gameplay is the same as Standard Mode.
In Solo, you play against Gaia. You play your turn like normal and then Gaia will “follow” your main action. Then Gaia plays its turn by drawing a card from a deck of 6 Gaia cards. You then “follow” Gaia's action and then Gaia plays her main action. Once the 6 cards are drawn, the deck is reshuffled and you play the next 6 turn. The game ends when the player finishes its 4x4 Tableau or when Gaia draws its last card.