Motivation

I want to create a game that can be played with pen and paper, like the original
battleship.
Also, it should have that non-abstract setting to it (in contrast to
tic-tac-toe, for example).
Battleship itself is a good start, but I dislike a couple of things about it:

• It does not have much tactical depth. Shooting chess-board-patters is the only
  strategy that makes sense, and beyond that, only luck will lead to victory.
• The different types of ships differ only in size, which effectively makes
  bigger ships worse, because they are easier to find.
• Ships are not allowed to move.
  One could argue that the battles are so fast that the ships cannot move far
  anyway, but still, I think this is a waste of potential.
• The only way of reconnaissance is shooting into the fog of war.
• Ships do not shoot themselfes, shots seem to come from off the map.

I am aware that there are different rule sets to make battleship more
interesting.
Some can be found on wikipedia and I got some ispiration from that, but I could
not find a particular set of rules that I liked.
Also, creating games is fun, so why not compose my own? 🙂

Rules

The map

Each player places their ships on a 12×12 grid.
The grid is divided into 16 sectors of the size 3×3, each.

  | A  B  C | D  E  F | G  H  I | J  K  L
--+---------+---------+---------+---------
01|         |         |         |
02|    I    |   II    |   III   |   IV
03|         |         |         |
--+---------+---------+---------+---------
04|         |         |         |
05|    V    |   VI    |   VII   |  VIII
06|         |         |         |
--+---------+---------+---------+---------
07|         |         |         |
08|   IX    |    X    |   XI    |   XII
09|         |         |         |
--+---------+---------+---------+---------
10|         |         |         |
l1|  XIII   |   XIV   |   XV    |   XVI
12|         |         |         |

The ships

The available ships are:

*) = means a simple occupied tile, O is the bridge.
> is the moving direction.

Carrier

The carrier can choose to launch a reconnaissance aircraft instead of shooting.
The acting player asks the opponent to disclose the fields of one chosen sector.
The opponent only names the occupied tiles, but not the exact ships.
Submarines are invisible to the aircraft.

Example:

    F | G H I | J
09    |       |
------+-------+---
10 [=|O=]   |
11    |       |
12   [|O=][=|

• A: “Launch aircraft to sector XIV.”
• O: “Occupied tiles are G10, H10 and I12.”

Unequally to shooting, starting an aircraft does not disclose the carrier’s
sector.
(A projectile comes from an unambiguous direction, an airplane can choose its
course.)

Battleship

Instead of shooting a single shot, the acting player can choose to shoot three
shots from the battleship instead of a single one.
This allows to hit more than one target, but immediately discloses the shooting
ship as the battleship.
The opponent will only announce the amount of hits, no the exact locations.

Example:

• A: “Shoot three shots from sector XI to A4, A5 and D1”.
  (The opponent now knows that the battleship’s brigde is in sector XI.)
• O: “Two hits.”

Destroyer

Instead of shooting, the destroyer can use sonar on a region to find submarines.
However, the sonar does not reveal the sub’s location, but only its course, that
is the line on which it is moving.
The sub may be in a completely different sector, though.

Example:

    C | D  E  F | G
------+---------+---
01    |       . |
02    |   II  . |
03    |       . |
------+---------+---
04    |      =|
05    |   VI  O |  

• A: “Using sonar on sector X.”
• O: “Find submarine on course F.”

If the courses of two subs cross the sector, both are revealed.
If two subs are on the same course, the course is still only reported once.

Unequally to shooting, using sonar does not disclose the destroyer’s sector.
(The listening is entirely passive.)

Submarine

The submarine is different to the other ship types, with multiple special rules:

• Moving:

  After shooting (or any special action), the acting player can move one
  submarine in the direction it is heading.
  They do so by writing a little arrow (“>”, ”

  After doing this multiple times, it will look like this:

                  [O  =]   |>>> |>
  

  The submarine is allowed tho dive beneath other ships, but not other
  submarines. They may move along the same course, thou

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