Spaceships - rules

1.: Introduction:
1.1.: Spaceships is a zero-sum game for two players, which can be played either as a single game or a series of games making up a scored match or continued match.
1.2.: It is played in two spaces, one for each player.
1.2.1.: Each space is a 3-dimensional 5x5x5 grid of cubical cells of which
1.2.2.: only the identity and relationship between the cells (not the size, exact shape, orientation or handedness) is relevant.
1.2.3.: Cells are adjacent if they share a face;
1.2.4.: cells are loosely adjacent if they share any face, edge or vertex.
1.2.5.: A set of several cells is said to be adjacent or loosely adjacent if each cell in the set is adjacent or loosely adjacent (respectively) to at least one other cell in the set.
1.2.6.: The spaces do not `wrap'.
1.3.: The object of the game is to cause all of your opponent's ships to be destroyed before they destroy yours.
1.4.: Spaceships is not a game of perfect information. Players record their play privately, revealing only certain information to each other, and
1.4.1.: reveal their records of their play for checking by the other player after each game is finished.
1.4.2.: Mutually trusting players need not reveal their records of the game to each other.

2.: A game consists of the following phases:
2.1.: Setup: each player secretly records[11.3] the locations and identities of their ships. [11.6], [11.6.1]
2.2.: Thereafter play proceeds in turns. During each turn:
2.2.1.: the two players first secretly record [11.5] their actions for that turn and the effects of those actions; when both players have done so
2.2.2.: each reveals the visible aspects of these actions to the other.
2.2.3.: Each player secretly records the effects of these visible aspects, and makes known their visible results.
2.2.4.: Finally (or earlier [11.7.3]), each player reports to the other the types, locations and identities of any of their ships which will be destroyed at the end of the turn, and flashcube data is exchanged.
2.2.5.: There is a conventional notation which includes a conventional coordinate system, and a conventional interaction ordering for the players' reports to each other.
2.2.6.: The actions, their availability, their effects and visible aspects, and the possible effects and visible results are defined in [4] and [5].
2.3.: Termination:
2.3.1.: If at the end of a turn either player has no ships which are not destroyed the game terminates immediately.
2.3.2.: If at the start of a turn either player has no possible actions other than kamikaze strikes and scans, and during that turn that player does not record any actions other than scans, then the game terminates at the end of the turn.
2.3.3.: A player's score in a game is the amount of remaining materiel they have when the game terminates.
2.3.4.: The winner of a game is the player with the higher score; if both players have the same score then the game is a draw.
2.3.5.: A player's remaining materiel is the number of undamaged cells in their ships.
2.4.: References to the state of a cell or ship refer to the state at the start of the turn, unless otherwise specified.

3.: A ship is a tuple consisting of
3.1.: a type,
3.2.: a subset of the cells in a player's space recorded as such by that player in the setup phase of the game, and
3.3.: an identity which distinguishes it from any other ships of the same type belonging to the same player.
3.4.: No two ships (belonging to the same player) may intersect.
3.5.: Each ship's subset of the space must conform to the shape requirements for its type.
3.6.: Each player must record exactly as many ships of each type as are in that player's fleet.
3.7.: Each player's fleet consists of a death star, a kill cruiser, either a flying saucer or a patrol cruiser, a missile destroyer, and either a light scout or a heavy scout, plus any additional ships due to to the rules for continued matches.
3.7.1.: Optionally, the players may agree that each player's fleet consists of any combination (or some restricted combination) of ships whose total cost is 24 (or some other number), plus any additional cost due to the rules for continued matches.
3.8.: After setup each cell belonging to a ship is either undamaged or destroyed. Every such cell is undamaged immediately after setup; it may become destroyed during the game.
3.9.: A ship is damaged when some but not all of its cells are destroyed.
3.10.: A ship is destroyed when all of its cells are destroyed.

4.: Actions:
4.1.: The player taking an action is called the active player; the other player is called the passive player. Note that in each turn each player is both the active player (with respect to their own actions) and the passive player (with respect to their opponent's).
4.2.: Each player may make in a turn any combination of their available actions insofar as they are permitted by the rules for those actions.
4.3.: The information to be recorded for each action and its effects and visible aspects are specified with each action in the list below:
4.4.: Conventional strikes:
4.4.1.: Unless otherwise stated, a single conventional strike may be launched per turn for every non-overlapping adjacent pair of undamaged cells belonging to the same ship.
4.4.2.: A conventional strike must be recorded as such together with the coordinates of the single target cell. [11.5.1]
4.4.3.: A conventional strike has no effects on the active player.
4.4.4.: The visible aspect of a conventional strike is a strike on the target cell.
4.5.: For each ship which does not entitle its player to a conventional strike or missile strike in a turn the player may instead launch one kamikaze strike in that turn:
4.5.1.: A kamikaze strike must be recorded as such together with the coordinates of the kamikaze launch and target cells. [11.5.5]
4.5.2.: The kamikaze launch cell must be an undamaged cell in the ship.
4.5.3.: Effect: the kamikaze launch cell becomes destroyed.
4.5.4.: The visible aspects of a kamikaze strike are a strike on the target cell and the kamikaze death of the kamikaze launch cell.
4.6.: A ship's type may entitle its player to additional actions due to special weapons or otherwise, or may modify the rules for the standard actions above.
4.7.: The active player need not record which strikes were enabled by which ships and rules.

5.: Visible aspects.
5.1.: For each possible visible aspect, the information to be passed to the passive player, the visible aspect's possible effects on the passive player and the corresponding visible results are specified in the list below:
5.2.: Strikes:
5.2.1.: A strike is identified as such and by the target cell in the passive player's space.
5.2.2.: If the target cell does not belong to a ship there is no effect on the passive player and the visible result is a miss.
5.2.3.: If the target cell belongs to a ship and is undamaged then the cell becomes destroyed and the visible result is a hit.
5.2.4.: If the target cell belongs to a ship and is destroyed when the strike is announced then there is no effect on the passive player and the visible result is a duplicate hit.
5.2.5.: Other rules may specifiy additional effects and visible results for a strike.
5.3.: A beam strike (the visible aspect of a beam weapon) has the same visible aspect, effects on the passive player and visible results as a strike, except that its visible aspect identifies it as beam strike rather than a strike.
5.4.: A kamikaze death
5.4.1.: is identified as such and by the kamikaze launch cell in the active player's space.
5.4.2.: A kamikaze death has no effect on the passive player and
5.4.3.: no visible results.

6.: Types of ships:
6.1.: Each type of ship
6.1.1.: contains a fixed number of cells,
6.1.2.: has a characteristic shape or set of shapes,
6.1.3.: has a cost, sometimes used for determining how many of each kind of ship are in each player's fleet,
6.1.4.: may have special weapons which entitle the ship's player to additional actions, and
6.1.5.: may have other properties which vary the effect of the other rules and/or specify additional rules, when events involve ships of that type.
6.2.: A death star
6.2.1.: contains eight cells,
6.2.2.: each of which is adjacent to at least two other cells in the death star,
6.2.3.: and it must contain either a 2x2x2 cube or a 3x2x1 rectangle, of adjacent cells.
6.2.4.: Each death star entitles its player to only one conventional strike per turn, but it does so until it is destroyed.
6.2.5.: Each death star has a beam weapon.
6.2.6.: A death star has a cost of 8.
6.3.: A kill cruiser
6.3.1.: contains six adjacent cells
6.3.2.: in a 3x2x1 rectangle, and
6.3.3.: has a cost of 6.
6.4.: A flying saucer
6.4.1.: contains four adjacent cells
6.4.2.: in a 2x2x1 square, and
6.4.3.: has a cost of 4.
6.5.: A patrol cruiser
6.5.1.: contains four adjacent cells
6.5.2.: lying in a straight line, and
6.5.3.: has a cost of 4.
6.6.: A missile destroyer
6.6.1.: contains three adjacent cells
6.6.2.: lying in a straight line,
6.6.3.: each of which is a missile, and
6.6.4.: has a cost of 3.
6.7.: A heavy scout
6.7.1.: contains two adjacent cells,
6.7.2.: has a scanner, and
6.7.3.: has a cost of 3.
6.8.: A light scout contains one cell,
6.8.1.: has a scanner,
6.8.2.: never entitles its player to a kamikaze strike, and
6.8.3.: has a cost of 3.
6.9.: An assault gunboat contains two adjacent cells,
6.9.1.: each of which is a missile, and
6.9.2.: has a cost of 2.
6.10.: A light gunboat contains one cell,
6.10.1.: which is a missile, and
6.10.2.: has a cost of 1.

7.: Flashcube data:
7.1.: When a player reports that one of their ships has been destroyed the other player must report flashcube data for the cells in their own space corresponding to the cells in the destroyed ship.
7.2.: Flashcube data for a cell identifies
7.2.1.: whether or not that cell is part of a ship, and for cells which are part of a ship:
7.2.2.: whether that cell is destroyed at the time the flashcube data is reported,
7.2.3.: the type of the ship containing the cell, and
7.2.4.: if the player has more than one ship of that type, the identity of the ship.

8.: Special weapons:
8.1.: A missile is either an unfired missile or a fired missile.
8.1.1.: After setup each missile starts as an unfired missile; it may become a fired missile during the game.
8.1.2.: A cell ceases to be a missile if it is destroyed.
8.1.3.: Each ship which contains an unfired missile entitles its player to exactly one missile strike as an additional action in that turn.
8.1.3.1.: A missile strike must be recorded as such together with the identity of the missile launch cell (which must be an unfired missile in the ship which enables the missile strike) and the target cell. [11.5.3]
8.1.3.2.: The effect of a missile strike (on the active player) is to cause the missile launch cell to become a fired missile just before the visible aspects are revealed[2.2.2].
8.1.3.3.: The visible aspect of a missile strike is a strike on the target cell.
8.1.4.: A strike whose target cell is still an unfired missile just after visible aspects are revealed additionally:
8.1.4.1.: has the effect on the passive player of causing any adjacent undamaged cells in the same ship to become destroyed and
8.1.4.2.: has as visible results missile explosions in the target cell and any adjacent undamaged cells in the same ship.
8.2.: Each ship with a beam weapon may entitle the player to one beam weapon firing per turn as an additional action.
8.2.1.: The visible effects of the beam weapon are beam strikes in three target cells, which
8.2.1.1.: lie in a straight line and
8.2.1.2.: are loosely adjacent.
8.2.2.: There must be two beam firing cells in the ship, such that the beam firing cells are
8.2.2.1.: undamaged,
8.2.2.2.: loosely adjacent and
8.2.2.3.: lie in a straight line parallel to that in which the target cells lie [8.2.1.1].
8.2.3.: A beam weapon firing must be recorded as such together with the identities of the target cells [11.5.2] and
8.2.3.1.: the type and identity of the ship whose beam weapon is being fired, if the player has several ships whose beam weapons could have enabled the firing; however,
8.2.3.2.: the identities of the beam firing cells need not be recorded.
8.2.4.: If a single beam weapon firing
8.2.4.1.: with only loosely adjacent target cells
8.2.4.2.: has any two beam strikes with as visible results hits in target cells which are not loosely adjacent
8.2.4.3.: then that beam weapon burns out.
8.3.: Each player who has an undestroyed scanner
8.3.1.: is entitled to one or more scans as additional actions.
8.3.1.1.: In turns after the first an undestroyed scanner entitles its player to one scan for each of their own ships' cells which became destroyed during the previous turn.
8.3.1.2.: In any case an undestroyed scanner entitles its player to at least one scan.
8.3.1.3.: Several undestroyed scanners entitle their player to only as many scans as a single undestroyed scanner.
8.3.2.: A scanner is destroyed when its ship is destroyed.
8.3.3.: A scan
8.3.3.1.: must be recorded as such together with the identity of the target cell. [11.5.4]
8.3.4.: The visible aspect of a scan is a scan in a target cell.
8.3.4.1.: The visible result of a scan identifies whether the target cell is part of a ship, and if it is whether that cell is destroyed when the scan is announced.
8.3.4.2.: A scan has no effect on either player.
8.4.: A weapon which burns out does not entitle the player to any actions in future turns in the same game.

9.: Scored matches:
9.1.: A pair of players may agree to play several games as a single scored match.
9.2.: There are no additional ships; each game is played independently, with each player having the usual choices for their fleet. [3.7]
9.3.: The condition for termination of the match must be agreed between the players, but
9.3.1.: the match should only terminate when a game has just terminated.
9.4.: Each player's overall score is the sum of their scores in all the games.
9.5.: The winner of the match is the player with the larger overall score; if both players have the same overall score then the match is a draw.

10.: Continued matches:
10.1.: A pair of players may agree to play several games as a single continued match.
10.2.: In every game except the first each player's fleet may contain some additional ships, as provided in this section.
10.3.: The additional ships must have a total cost equal to the player's remaining materiel at the end of the last game.
10.4.: The players need not inform each other of the number and types of their additional ships.
10.5.: Players may choose before the start of the match to restrict the numbers or types of additional ships which will be allowed.
10.6.: The condition for termination of the match, and the victory condition, must be agreed between the players, but
10.6.1.: the match should only terminate when a game has just terminated.

11.: Conventional notation:
11.1.: There is some conventional notation for recording information required by the game and information which the players may find helpful.
11.2.: Conventional notation need not be used, but
11.2.1.: unless the players are mutually trusting the players must make the records required by the game in an unambiguous fashion.
11.3.: Each player keeps a two sets of five 5x5 square grids representing the players' spaces in which they record
11.3.1.: the locations and identities of their own ships (recorded during setup);
11.3.2.: the state of their own ships, as modified during the game, including whether each cell is destroyed and whether missiles have been fired;
11.3.3.: optionally, their opponent's actions' visible aspects;
11.3.4.: the visible results of their own actions;
11.3.5.: and the locations and states of their opponent's ships, as and when this information becomes known.
11.4.: The cells are identified by their three cartesian coordinates. The three coordinates and their values and orderings are:
11.4.1.: colour: Red, Orange, Yellow, Green, Blue, abbreviated R O Y G B.
11.4.2.: letter: v, w, x, y, z.
11.4.3.: number: 1, 2, 3, 4, 5.
11.4.4.: The order for writing down and reading out coordinates is colour, letter, number. Coordinates are usually written as triples of characters without spaces.
11.4.5.: Case is significant in the notation; it is required for distinguishing Y (Yellow) from y.
11.5.: Actions are conventionally recorded for each turn as a list of zero or more the following:
11.5.1.: Each conventional strike is recorded as the triple for the coordinates of the target cell.
11.5.2.: Each use of a beam weapon is recorded as b followed by the coordinates of the two end cells which together identify the line of target cells;
11.5.2.1.: if several ships could have enabled this beam weapon firing then the type and identity of the ship whose beam weapon is being fired are recorded in parentheses after those coordinates.
11.5.3.: Each missile strike is recorded as m followed by sufficient coordinate value(s) to uniquely identify the missile launch cell, and as one additional strike target cell[11.5.1].
11.5.4.: Each scan is recorded as s followed by the coordinates of the target cell.
11.5.5.: Each kamikaze strike is recorded as k followed by the coordinates of the kamikaze launch cell, and as one additional strike target cell[11.5.1].
11.6.: Ship types are recorded using the two initial letters of the type, in capitals;
11.6.1.: if several ships of the same type are present their identities are consecutive increasing integers starting at 1, and
11.6.2.: the ship's type and identity are together written as the initial letters of its type [11.6] immediately followed by its identity.
11.7.: Ordering of interaction between the players:
11.7.1.: One player (the initially active player) should report all of the visible aspects of their actions in a turn before the other player does the same.
11.7.1.1.: The active player should first report any beam strikes, then any strikes, then any scans, then any kamikaze deaths.
11.7.1.2.: It is not necessary to report which strikes were the visible aspects of conventional strikes, missile strikes or kamikaze strikes.
11.7.1.3.: For each action the visible results should be reported immediately by the passive player.
11.7.2.: When one player's actions' visible aspects have been dealt with then the other player reports the visible aspects of their actions.
11.7.2.1.: Players may choose to alternate between initially being the active player or passive player in successive turns, or may fix an order. The order of reporting has no effect on the play of the game.
11.7.3.: A player should make destruction of a ship known [2.2.4] to their opponent during the reporting of visible aspects and visible results together with the visible aspect or result which is associated with the destruction of the ship's last undestroyed cell.
11.7.3.1.: Flashcube data is returned as soon as a player reports the destruction of a ship.

12.: Acknowledgements, copyright, &c.:
12.1.: Spaceships was originally devised by Sion Arrowsmith;
12.2.: this ruleset was adapted from the original rules by Ian Jackson with suggestions from David Damerell and others.
12.3.: These rules were written and formatted by Ian Jackson and are Copyright 1997 Ian Jackson,
12.3.1.: as are the SGML DTD and processing system which were used to format them, except that
12.4.: This is version 2.6.1 of these rules.