TCOTA - Rules

From The Open Source Board Game

The Cities of the Aeronauts is a game that can be played with varying degrees of complexity. This page is the complete rule book for the base game set, rules for expansion packs are linked to from that relevant pack's page.


Utadiun explorers have just found a new island with abundant natural resources, ripe for settlement. A number of cities from the mainland have launched settlement airships to colonise this new land. The Guild of the Merchants has offered a lucrative trade deal, along with a number of other rewards, to the first city in the new land that grows to meet their criteria. Each of you, as leaders of your own settlements, must work to ensure your city gets that deal.


The Merchants will offer their deal to the first self-sufficient city in the new land that is also capable of withstanding attacks from enemies. This means lasting two rounds without relying on trade with the mainland or with any other players.


Starting the Game[edit]

What to do on your turn[edit]


Action Phase[edit]

Initiating Combat[edit]

Combat is initiated during this phase when a player moves one of his military vehicles onto a space that is adjacent to another player's piece (combat cannot be initiated between two pieces that were already adjacent at the beginning of the turn).

Combat is only averted if both players declare peaceful intentions. The player making the move is required to declare his intention first, whether it be peaceful or whether they intend to attack. The player being moved against will then either defend his position if they are attacked, or if peaceful intentions were declared, they can accept the peace offer and avoid conflict, or take the opportunity and attack the player that moved against them.

If combat is initiated, the player that initiated the conflict places their combat flag onto the piece he is attacking. The player, whose turn it is, then continues their turn as normal. Combat initiated during the Action Phase is resolved during the Combat Phase.

A few rules govern the initiation of combat:

  1. A player can only attack one target per turn.
  2. A player can attack their target with up to 6 military airships, by moving those ships within a 1 hex radius of (i.e. adjacent to) the piece being attacked.
  3. The defending player cannot move the piece that is getting attacked.
  4. The defending player can get reinforcements to the area to assist, by moving those ships within a 2 hex radius of their attacked piece.
  5. When a player's city is attacked; the radii for the accumulation of attacking and defending ships is increased to 2 hex and 3 hex, respectively.

Combat Phase[edit]

Combat is a big part of The Cities of The Aeronauts, and as such, there is an entire phase dedicated to it. Combat that has been initiated during the action phase is resolved in this phase with a method we hope is an engaging combination of luck and determination.


Once the Combat Phase begins, conflicts are resolved one-by-one in the order they were initiated.

Deck Prep[edit]

Both the attacking player and the defending player must remove from their hand, and place on the table, the vehicle and building cards that correspond to the vehicles and/or buildings involved in the combat. These cards are associated with the pieces in combat and are returned to the box along with their associated piece if they are taken out.

Each player counts the action points for their pieces and then builds a Combat Sequence from their Combat Cards Deck. The total action value of cards in the Combat Sequence must not exceed the total action points available from their pieces.

Both players order their cards in whatever way they choose, but once the combat starts, they cannot make any changes and can only deal from the top of their prepared Combat Sequence.


Combat involves both players dealing one card each, simultaneously, from their Combat Sequence.

For each deal, the winning card is left on the table and the losing card discarded to the player's Combat Card pile. If both players deal the same card, both cards are added to the winning pile.

Instructions on special cards are followed immediately after they are dealt. The card dealt against the special card remains in play and opposes the next card dealt after the special. If two special cards are dealt simultaneously, the instructions are followed for both and then dealing continues.

Dealing continues until one (or both) of the players run out of cards; once this happens, if the other player still has cards remaining, he places them onto the winning pile.


Alternate more determinate play as follows:

Combat involves attacking player dealing from their sequence, while the defending player has the option to either counter with the top card from their sequence or to take the blow.


After the cards are all dealt, the damage points for each winning defence and attack card is tallied up, giving a defending and an attacking score.

If the total attacking score is greater than the hitpoints of the piece being attacked, subtract the hitpoints from the attacking score and remove that piece from the board and return it to the box along with its corresponding card. If the attacking score was less than its hit points, the piece that was attacked stays on the board and the attacking score is reduced by 25% (rounded down to the whole number).

Then begin to eliminate the defending force, if any, starting with the piece with the lowest action points. If the remaining attacking score is greater than the piece's hitpoints, remove the piece from the board, and subtract the hitpoints from the attacking score. Repeat until there are no defending ships left or the attacking score is too low to remove the next piece.

Then begin to eliminate the attacking force using the same method, beginning with the piece with the lowest action points. If the defending score is higher than the hit points of the attacking piece, remove that piece from the board and return it to the box (along with its corresponding vehicle card), and subtract its hitpoint from the defending score. Repeat this, moving from the pieces with the lowest to highest action points, until there is either no attacking pieces left on the board or the current defending score is too low to remove the next ship in line.

The table below gives an example of attack scoring where the attacking force did not take the attacked piece, nor did they destroy the defending force.

Attacking Score Hitpoints of Defending Force and the Attacked Piece
Attacked Piece: Transport Cutter Cutter Transport Dreadnaught
25 30 7 7 30 25
Attack on Transport fails. Score reduced to 18
18 30 7 7 30 25
Cutter eliminated. Score reduced to 11
11 30 7 30 25
Cutter eliminated. Score reduced to 4
4 30 30 25
Unable to progress further
End of Attack Scoring

This table gives an example of scoring an attack where the defence destroyed all the attacking ships.

Defending Score Hitpoints of Attacking Ships
Cutter Cutter Transport Battleship
60 7 7 30 15
Cutter eliminated. Score reduced to 53
53 7 30 15
Cutter eliminated. Score reduced to 46
46 30 15
Transport eliminated. Score reduced to 16
16 15
Battleship eliminated. Score reduced to 1
Attacking Force is completely destroyed.
End of Attack Scoring


Trading takes place after the 'Combat' phase of a round, and players bid and settle on trades of goods. There is no universal currency so this runs entirely based on each player's perceived value of the goods. Once the trades have been settled, the goods are placed on to that city's relevant 'export to...' card, and will be unavailable until the merchant completes the delivery.

The merchant ships travel independently around the board, picking up and delivering goods. The number of merchant ships is directly proportional to the number of docks that are available across the map. Their AI is simple, they will pick up one trade-worth of cargo from the current city and then deliver it, and then repeat. They cannot carry cargo from multiple trades unless it is all going to the same city (which means it really is just the same trade). If there are multiple cargos for multiple destinations and not enough merchants, the merchants available will pick the largest ones to deliver first (largest means the trade with the biggest number of resource tokens, not value).

Merchants pick up goods by moving the goods from the relevant 'export' card to their ship card. Once they reach their destination they move the resources to the inventory of that city.

Other Ways to Play[edit]