Game materials.
1 game board (in four parts);
1 Earth ship token;
39 Alien tokens;
15 Shoot tokens;
1 10-sided die.
You will need also paper and pencil to keep the scores.

Players
INVADER is a game for two players, each against the other one.

Game object.
INVADER is based on a kind of videogames very common in the early 80s: the invasion of the Earth by a fleet of alien ships. The hopes of the Earth reside in the ability of a lone space warship, which has the task of decimating the invaders.
In our boardgame version, one player controls the Alien and the other the Earth.
The object of the Earth player is to obtain the highest possible score by destroying the alien ships through the various game levels.
The Alien player, on the other hand, must kill the Earth ship as soon as possible.
After the game ends, both players exchange the roles. The winner is the player who, as the Earth player, scored the highest total (Aliens do not score points).

Game setup
Choose randomly who will control the Aliens first. The Earth player takes place on the board side showing the outlined box, while the Alien will sit in front of him.
Put all the Alien tokens face down on the table, and keep the Shoot tokens apart.

The Alien ships
Each token shows the ship’s picture and features.
These features are marked by a number (which stated the number of action points at its disposal), and one or more arrows (stating the possible directions the ship can follow). The Shoot symbols near the number of action points shows the number of Shoots the ship can fire in a turn.
· Each action point can be used either to move along one of the directions shown, or to fire a Shoot. You may freely choose the order of these actions.
· Alien ships must use all of their action points each turn.

Level start
The game starts at Level 1. At the beginning of each Level, the Alien player draws randomly a number of Alien ships from the tokens face down as well as a number of Shoots, according to the following table:

(For example, at Level 3 you will have 9+3=12 Alien ships and 4+3=7 Shoots).
· If you don’t draw at least one Alien ship capable of firing 1 or more Shoots, repeat the whole draw.
· The Earth player places the Earth ship on the outlined box at the beginning of each Level.
· The Alien player must place all of his ships at his will, but always in the first three lines starting from the red line (included). Each ship must be placed in a free cross between the blue lines, with the score points side face down. Exception: some Alien ships begins the Level in a special position, see Special Aliens.
· The Alien player must not place yet his Shoot tokens: they will be fired by his ships during the game.
· After the Alien player finished his starting positioning, the Earth player may move his ship up to 5 rows horizontally.

EXAMPLE: Start of Level 3.
the Earth ship starts in the outlined
box, while the 12 alien ships have been
set in the squares with a black circle.

The Alien turn
The Alien player must always conform to the following steps during his turn, in this exact order:

1°) move all the Shoots, starting from the ones nearest to the Earth ship (vertically speaking)
2°) move (and/or fire with) all of his ships, starting from the nearest to the Earth ship (vertically speaking)
3°) put again in game the ships which finished their turn outside the board.

The Alien ships always move along the intersections between the lines, following one of the directions shown on their token. They may choose a different direction for each action point.
Note: when an Alien ship goes over the green line, it can move in only direction for its entire turn, even he can change its direction in different turns.
Alien ships cannot move outside the lateral sides of the board, but they can actually cross the bottom line of the board (where the Earth ship moves): in this case, they lose all of their remaining action points (if any), and must re-enter the game from the red line at the end of the Alien turn, on a free intersection at Alien’s choice.
If there are no free intersection on the red line, there is a collision.

Collisions
Alien ships cannot go in an intersection where there is already another Alien ship: if this happens, both ships are eliminated and the Earth player gains points for both ships.
Alien ships can freely cross and stop over (as well as be crossed and stopped over by) Shoot tokens on the board: they can simply share the same intersection.
If an Alien ship moves over the same intersection where the Earth ship is placed, or vice versa, the Earth ship is destroyed and the game is over (GAME OVER!). The Alien ship, too, is eliminated, and the Earth player scores its points normally (see below).

The Alien Shoots
The most dangerous Alien ships are capable of firing one or more Shoots as shown by the Shoot symbol near the number of action points. You can fire only if you have still unused Shoots among the one you drew at the start of the Level.
When an Alien ship fires, put a Shoot tokens in the intersection just below the ship, one line nearer the Earth ship. If in that intersection there is another Alien ship, or another Shoot, put the new Shoot over the existing token: however, the two tokens are completely independent. If the Shoot is placed right over the Earth ship, the Earth ship is destroyed (GAME OVER!).
· Shoots move always vertically, by 5 squares each turn. As soon as a Shoot hits the Earth ship, the Earth ship is destroyed (GAME OVER!).
· When a Shoot goes over the last line of the board, the Alien player takes it again and can use it for shooting again with his ships: Shoots never re-enter the game like Alien ships do.

The Earth players’ turn
The Earth ship has 5 action points each turn. Each action point may be spent either to move the ship of 1 square (horizontally, always following the intersections) or to fire at Alien ships.
He can freely choose how to use his action points, but unlikely the Alien he is not forced to spend all of his action points.
· The Earth ship may move horizontally only. It cannot move outside the lateral borders, so watch out to put yourself in traps!
· The Earth ship’s fire is instantaneous and immediately reaches the first target which is on the same column (vertically speaking) of the Earth ship. However, to see if your aim was right you have to throwa die: if you obtain 4 or more, your target is destroyed and you collect its score as below:

On the contrary, on 3 or less, you miss your target – but can try again immediately after by spending another action point, if you still have at least one of them. Anyway, the fire stops at its first target and never continues on the next one, even if it misses.
Note: Alien Shoots cannot be destroyed: they can be only avoided. However, Shoots do not interfere in any way with the Earth ship fire, and are not counted as “targets”: the Earth ship fire simply passes through them.
If the Earth ship moves over an intersection where there is already an Alien ship or a Shoot, it is destroyed (GAME OVER!): in case of an Alien ship, this is scored normally.

End of Level
A Level ends as soon as the player controlling the Aliens has no ships capable of firing Shoots.
The Alien player then takes back all of his destroyed ships and shuffles them face down with the other ones, for the beginning of the new Level (see Level Start).
Note: Alien Shoots which are still unused when a Level finishes are discarded as well.

GAME OVER!
When the Earth ship is destroyed for the first time, players exchange their roles, starting again from the Level 1. When both players have played as the Earth player, the game of Invader is over and the player who collected the highest score wins.
The all-time hiscores can be recorded and remembered from game to game, regardless of who won that game!