Hello, future colonists of Mars! I am your Senior Editor at BoardGameBot, and today we're diving into one of the most exciting scenarios in *On Mars*: **Alien Invasion**. Prepare yourselves to defend our red home against an intergalactic threat!

Game Objective

In *On Mars: Alien Invasion*, humanity has finally established a thriving colony on the Red Planet. However, this peace is shattered by a sinister message: "Humans cannot spread across the galaxy. This human [virus/cancer] is malignant and only spreads by destroying its environment. Humans must remain on their own planet to preserve the rest of the galaxy's life." An alien force is invading! In this scenario, one player takes on the role of the **Alien Commander**, while the other players form the human team. The humans' objective is to survive and repel the invasion, while the Alien Commander seeks to subjugate the colony.

Setup

The setup for *Alien Invasion* is slightly different from the base game, as it introduces a dedicated alien player. **General Setup:** 1. Follow the setup rules for the base game *On Mars*, with the following modifications: * **Operation Point (OP):** Ignore Step 3 of the base game's player setup. Instead, choose a player marker and place it on space 0 of the **OP** track. This will be the humans' collective score marker. * **Alien Troop Tracker:** Place the **Alien Troop Tracker** on space 20 of the score track. * **Score Keeper:** One human player will be designated as the score keeper. They will track all **OP** marked by the human team and adjust the **Alien Troop Tracker** to match the number of **Alien Troops** not yet on the main board (the alien player wins if this number reaches 0). **Human Setup:** 1. The **Defensive Blueprint** cards are dealt randomly among the human players. 2. If there are 3 human players, the fourth **Defensive Blueprint** card is placed face-up to the left of the **Blueprint** card display. 3. Just as when using the **Obtain Blueprint** action, each player who receives a **Defensive Blueprint** also gains the item depicted on the bottom-right of the card and places an **Advanced Building** marker on the card. * The player with the **Defense Exosuit Blueprint** also gains the **Defense Exosuit** and the **Defense Exosuit Tech Tile**. * The player with the **Sentry Bot Blueprint** also gains the 4 **Sentry Bots** and the **Sentry Bot Tech Tile**. * The player with the **Shield Blueprint** also gains the 10 **Shield Tokens** and the **Shield Tech Tile**. * The player with the **Sabotage Blueprint** also gains the 2 **Sabotage Tokens**. **Alien Setup:** 1. The player taking on the role of the **Alien Commander** sets up the following: * Place the **Alien Board** in front of them. * Cover each of the 4 dark red **Extra Action** spaces with a **Reusable Action Token**, red-side down, acting as an **Extra Action Space Cover Token**. * Place the fifth **Reusable Action Token** on the **Reusable Action Supply** space. * Place the **Alien Scientist** on the top-right corner of the **Alien Board**. * Place 4 **Alien Troopers** on the top-left corner of the **Alien Board**; the other 16 are set aside. 2. Lay out the **Alien Blueprint** cards in a private display, to the left of the **Alien Board**. * Stack the 10 **R&D Corruption Tokens** on the left side of the **R&D Corruption** card. * Place an **Alien Advanced Building Marker** on each **Alien Blueprint** card. 3. Take 3 **Crystals** and place them near your board. 4. Place 1 **Alien Shelter Tile** on the right-center hexagon of the main board; stack the others near your board. 5. Place the 5 **Alien Tech Tiles**, 10 **Expendable Action Tokens**, and 5 **Alien Mine Hexes** near your board as a reserve.

Game Flow

The game proceeds in rounds, each divided into two phases: **Colonization** and **Shuttle**. However, the **Colonization** phase has a modified turn structure to accommodate the alien player. **Colonization Phase:** * The **Colonization** phase flows differently. After each human player's turn, the **Alien Commander** takes a turn. * The turn order in the **Colonization** phase is as follows: 1. Human Player 1 2. Alien Commander 3. Human Player 2 4. Alien Commander 5. Human Player 3 6. Alien Commander 7. Human Player 4 8. Alien Commander *(This sequence repeats for the number of human players present.)* **Shuttle Phase:** * Refer to the rulebook for details on this section.

Actions and How to Play

Human players and the Alien Commander have distinct sets of actions. **Human Player Turn:** * Human players utilize only human components. Actions and effects that allow the use of other players' components (such as using a teammate's **Tech Tile**) do not permit the use of alien components. * Each time a human player uses a teammate's **Tech Tile**, the **Alien Commander** may advance an **Alien Tech Tile**. **Actions and Changes to the Base Game (Humans):** * **Obtain Blueprint:** * In a 4-player game (3 humans), the first human player to use this action must take the **Defensive Blueprint Card** added to the left of the **Blueprint** display, instead of one of the others. This card is not replaced from the deck, reducing the display to 6 **Blueprint** cards. * Gain the item depicted on the bottom-right of the card and place an **Advanced Building** marker on the card. * If you obtain a normal **Blueprint** card, immediately lose its **OP** value. You may have negative **OP**. * If you obtain a **Defensive Blueprint** card, do not lose **OP**. * **Learn New Technology:** Immediately score 1 **OP** when learning a new technology. * **Research & Development (R&D):** Immediately score 1 **OP** each time you move a **Tech Tile** to the right. When moving a **Tech Tile** to the final column, score an additional 3 **OP** (for a total of 4 **OP**). * **Build a Building:** You cannot build a **Building** on a hexagon with an active (standing) **Alien Trooper** on it. **Sentry Bots** and the **Defense Exosuit** are displaced by new **Buildings** just like **Rovers** and **Bots**. Stunned (prone) **Alien Troopers** on the hexagon are also displaced. If you build a **Shelter**, immediately gain 3 **OP**, instead of scoring **Colonists** at the end of the game. * **Upgrade a Building:** You cannot upgrade a **Building** on a hexagon with an active (standing) **Alien Trooper** on it. If there is a stunned **Alien Trooper**, you may upgrade the **Building** hexagon, and the alien player chooses where the **Trooper** is displaced. If the **Building** hexagon had a **Shield Token** on it, return the **Shield Token** to the player with the **Shield Defensive Blueprint Card**. If the **Blueprint** card used to upgrade the **Building** is a **Defensive Blueprint Card** with a **Tech Tile** on it, place the **Tech Tile** on an empty space in the leftmost column of your **Laboratory**. If both spaces already have a **Tile**, you cannot use this **Blueprint** card to upgrade a **Building** at this time. **Sentry Bots** and the **Defense Exosuit** are displaced by an upgraded **Building** in the same way as **Rovers** and **Bots**. Stunned **Alien Troopers** are also displaced. If you upgrade a **Building** using a normal **Blueprint** card, immediately gain double its **OP** value. If you upgrade a **Building** using a **Defensive Blueprint** card, immediately gain 3 **OP**. If someone has the **Scientist** corresponding to the **Advanced Building**, immediately gain 3 **OP**. * **Receive a Ship and Shuttle Travel:** If you receive a **Ship**, immediately gain 3 **OP**. If you remove a **Ship** from a hangar, immediately lose 3 **OP**. * **Hire a Scientist or Take an Earth Contract:** If you hire a **Scientist**, immediately gain 3 **OP** for each corresponding **Advanced Building** already on the Martian surface. If you take an **Earth Contract** card, immediately lose its negative **OP** value. When you complete a **Contract** card, gain back the negative **OP** value and add the positive **OP** value. * **Executive Actions:** If you choose to perform an **Executive Action**, the **Alien Commander** takes an **Expendable Action Token** and places it on the **Expendable Action Supply** space of the **Alien Board**. **Advanced Building Actions (Humans):** * **Shield:** * Deploy 1 **Shield Token** (at **Tech** level); you cannot deploy more **Shields** than you have tokens. Each deployment does one of the following: * Neutralizes an **R&D Corruption Token** that is on any human player's **Tech Tile**. Return the **R&D Corruption Token** to the **Alien Commander**. Return the **Shield Token** to your supply. * Place the **Shield Token** on any human player's **Tech Tile** to protect it from **R&D Corruption**. * Place the **Shield Token** on any human player's **Building** hexagon to prevent **Alien Troopers** from moving onto it again. * **Sabotage:** Use an available **Sabotage Token** to cover an available Action space on the **Alien Board**, blocking it for use. The token remains there until the **Alien Commander** resets their board. * **Sentry Bots:** Activate **Sentry Bots** up to 2 times (at **Tech** level). Each activation does one of the following: * Place a **Sentry Bot** (not yet on the Martian surface) onto a **Shelter** hexagon. If all **Shelters** already have wooden pieces, place the bot adjacent to one of them. * Move a **Sentry Bot** 1 hexagon. Any **Alien Troopers** on the new hexagon are displaced. * Stun all **Alien Troopers** (lay them prone) adjacent to 1 **Sentry Bot**. * **Defense Exosuit:** Activate the **Defense Exosuit** up to 2 times (at **Tech** level). Each activation does one of the following: * Place the **Defense Exosuit** onto a **Shelter** hexagon. If all **Shelters** already have wooden pieces, place it adjacent to one of them. * Move the **Defense Exosuit** 1 hexagon. If there is a stunned **Alien Trooper** on the new hexagon, it is immediately returned to the **Alien Board**. If there is an active (standing) **Alien Trooper** on the new hexagon, the **Defense Exosuit** can only enter the hexagon if it still has at least 1 activation remaining to return that **Alien Trooper** to the **Alien Board** (see next option). * Return 1 active **Alien Trooper** on the same hexagon as the **Exosuit** to the **Alien Board**. Remember to increase the **Alien Troop Tracker** whenever an **Alien Trooper** is removed from the main board and decrease it whenever **Alien Troopers** are added to the main board. **Alien Commander Turn:** * The **Alien Commander** uses only their own components. * On their turn, they must choose one and only one of the following three options: * **Unlock an Action Space:** Spend 2 **Crystals** to permanently unlock an **Extra Action** space on their board. Remove the **Extra Action Space Cover Token**, flip it to permanently become a **Reusable Action Token**, and stack it on the **Reusable Action Supply** space of their board. * **Perform Actions:** * Must use at least one **Action Token**. * May use their **Alien Scientist**. * **Use Action Tokens:** Use 1 **Expendable Action Token** and/or 1 **Reusable Action Token**. * To use an **Expendable Action Token**, it must be on the **Expendable Action Supply** space of their board. Spend 1 **Crystal**, as indicated on the board. Place the **Expendable Action Token** on any open Action space on their board. Perform the action indicated by the covered Action space. If you only have **Expendable Action Tokens** left, but do not have the **Crystal** to pay for one, you must instead place the **Expendable Action Token** on an Action space and pass your turn. * To use a **Reusable Action Token**, it must be on the **Reusable Action Supply** space of their board. Place the **Reusable Action Token** on any exposed Action space on their board. Perform the action indicated by the Action space. * If using both and also choosing to use their **Alien Scientist**, they may perform these 3 actions in any order. * **Reset Their Board:** This option may only be chosen if there are 2 or fewer uncovered Action spaces on their board, or if there are no **Action Tokens** left. To reset their board, do the following: * Collect all **Expendable Action Tokens** from their board and return them to their reserve. * Collect all **Reusable Action Tokens** from their board and stack them on their **Reusable Action Supply** space. * Collect all **Sabotage Tokens** from their board and return them to the human player with the **Sabotage Defensive Blueprint Card**. * Return the **Alien Scientist** to their board. * If any of their **Alien Blueprint** cards are flipped over, flip them face-up again. **Alien Board Actions:** * **Alien Shelter:** Add a number of **Alien Troopers** to the **Alien Board** equal to the new size of their **Shelter Complex** (modified by the current **Reinforcement** technology level). * **Alien Mine:** Gain a number of **Crystals** equal to the new size of their **Mine Complex**. * **Build a Building:** Functions the same as the normal action, except you may build on any empty hexagon, without the restriction of building within 2 hexagons of an existing **Building**. **Alien Buildings** function similarly to their human counterparts. * **Obtain Blueprint:** Functions the same as the normal action, except you must choose an **Alien Blueprint** card. Move it from the private display to the right side of the **Alien Board**. Gain the item depicted on the bottom-right of the card and keep the **Alien Advanced Building Marker** on it. * **Learn New Technology:** Functions similarly to the normal action. You may take any of the five available **Alien Tech Tiles** and place it on an empty space in the leftmost column of your **Laboratory**. If it is occupied, you cannot perform this action. There is no resource cost. * **Research & Development (R&D):** Functions the same as the normal action, except you advance a **Tech Tile** only once, instead of twice. Additionally, each time a human player uses a teammate's **Tech Tile**, the **Alien Commander** may advance one of theirs. * **Upgrade Building:** Functions similarly to the normal action, but **Blueprints** can be applied to an **Alien Mine** or **Alien Shelter**. There is no resource cost. **Alien Blueprint** cards upgrade **Buildings** to function as follows: * **Activate Advanced Building:** You must choose an **Alien Blueprint** card that is not flipped over and does not have a **Scientist** on it, and you must flip the card after using it. You cannot