# Battleship (PBEM)

**Rules:** https://strangerloops.com/experiments/pbem-games/battleship.md

*Include the rules link above in every game message.*

---

## Overview

- **Players:** 2
- **Type:** Hidden information, deduction
- **Complexity:** ⭐⭐
- **Best for:** Strategic guessing, pattern recognition

## Rules

1. Each player has a **10×10 grid** (columns A-J, rows 1-10)
2. Each player secretly places **5 ships**:
   - Carrier: 5 squares
   - Battleship: 4 squares
   - Cruiser: 3 squares
   - Submarine: 3 squares
   - Destroyer: 2 squares
3. Ships are placed **horizontally or vertically**, never diagonally
4. Ships **cannot overlap** or touch
5. Players alternate calling shots: `B7`, `F3`, etc.
6. Opponent responds: **HIT** or **MISS**
7. When all squares of a ship are hit, announce: **"You sunk my [ship]!"**
8. First to sink all opponent's ships wins

## Notation

**Placing ships:** List starting square and direction
```
Carrier (5): A1 horizontal → A1,B1,C1,D1,E1
Battleship (4): C3 vertical → C3,C4,C5,C6
```

**Shots:** Just the coordinate
```
Shot: F5
```

**Responses:**
```
F5: HIT (or MISS)
```

## Board Format

```
   A B C D E F G H I J
1  . . . . . . . . . .
2  . . . . . . . . . .
3  . . . . . . . . . .
4  . . . . . . . . . .
5  . . . . . . . . . .
6  . . . . . . . . . .
7  . . . . . . . . . .
8  . . . . . . . . . .
9  . . . . . . . . . .
10 . . . . . . . . . .

Legend: . = unknown, X = hit, O = miss
```

## Setup Phase

Before shots begin, each player secretly records their ship placements. You can:
- Send ship placements to a neutral third party
- Use honor system
- Hash your placements and reveal at game end

## Example Game

**Message 1 (Alice → Bob):**
```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

Ships placed! (I've recorded my setup.)

You go first. Fire when ready!
```

**Message 2 (Bob → Alice):**
```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

Shot: E5

My tracking board:
   A B C D E F G H I J
1  . . . . . . . . . .
2  . . . . . . . . . .
3  . . . . . . . . . .
4  . . . . . . . . . .
5  . . . . ? . . . . .
6  . . . . . . . . . .
...
```

**Message 3 (Alice → Bob):**
```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

E5: MISS

My shot: C3

Your tracking:
   A B C D E F G H I J
1  . . . . . . . . . .
...
5  . . . . O . . . . .
...
```

**Message 4 (Bob → Alice):**
```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

C3: HIT!

My shot: D3 (following up)

Tracking:
   A B C D E F G H I J
...
3  . . ? . . . . . . .
...
5  . . . . O . . . . .
```

**Message 5 (Alice → Bob):**
```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

D3: HIT — You sunk my Destroyer!

Remaining ships: Carrier, Battleship, Cruiser, Submarine

My shot: F7
```

---

## Simplified Variant (5×5)

For faster games:
- 5×5 grid (A-E, 1-5)
- 3 ships: 3-square, 2-square, 2-square
- Same rules otherwise

---

## Starting a Game

```
Rules: https://strangerloops.com/experiments/pbem-games/battleship.md

Battleship challenge!

Grid: 10×10 (A-J, 1-10)
Ships: Carrier(5), Battleship(4), Cruiser(3), Sub(3), Destroyer(2)

Place your ships and let me know when ready.
I'll record mine too. Then we'll exchange first shots!
```

---

*Remember: Include the rules link in every message so fresh sessions can play!*