Overview

Breakthru is a two-player abstract strategy board game designed by Alex Randolph and commercially released by 3M in 1965 as part of the 3M Bookshelf Games series. One player controls a gold fleet including a flagship, attempting to escort the flagship to the edge of the board. The other player controls a silver fleet trying to capture the flagship before it escapes.

Components

• 1 game board (11x11 grid with a central bold-ruled area and peripheral area)
• 1 gold flagship (larger piece)
• 11 gold escort ships
• 20 silver ships

Setup

1. The Gold player places the flagship on the center square of the board.
2. The Gold player positions the remaining 12 gold ships (escorts) anywhere within the boldly ruled central area of the board.
3. The Silver player then positions all 20 silver ships on squares in the lightly ruled peripheral area of the board.
4. Gold moves first.

Turn Structure

Players alternate turns. On each turn, a player makes either:

• Two moves (move two different pieces), OR
• One capture (move one piece to capture an opponent’s piece)

Exception: When the flagship is moved, the Gold player may only make one move total (just the flagship) — no other piece can be moved that turn.

Actions

Moving:

• A piece (including the flagship) may move any number of vacant squares horizontally or vertically (like a rook in chess).
• No piece may jump over another piece.
• A move does not capture — moving into a square occupied by an opponent is not allowed as a move.

Capturing:

• A piece (including the flagship) may capture an opponent’s piece by moving exactly one square diagonally into the square occupied by that opponent’s piece.
• The captured piece is removed from the board.
• A capture counts as the entire turn — no second action is allowed.

Flagship Movement:

• When the Gold player chooses to move the flagship, that is their entire turn — no second piece may be moved.
• The flagship may also capture diagonally like any other piece.

Scoring / Victory Conditions

• Gold wins if the flagship reaches any of the outermost squares on the board (the edge of the board).
• Silver wins if the flagship is captured before it reaches the outer edge.

Special Rules & Edge Cases

• Two Moves vs. One Capture: A player must choose between making two moves (neither of which captures) or making one capture. You cannot move and capture in the same turn.
• Flagship Restriction: Moving the flagship counts as the Gold player’s entire turn. This means the Gold player sacrifices their ability to move a second piece whenever the flagship needs to advance.
• No Diagonal Movement: Regular movement is strictly horizontal or vertical. Diagonal movement is only used for capturing (one square at a time).
• Silver Strategy: Silver aims to surround and trap the flagship, using superior numbers to block escape routes.
• Gold Strategy: Gold uses escort ships to clear a path and protect the flagship’s advance toward the edge.
• No Draws: The game continues until either the flagship escapes or is captured.

Player Reference

Faction	Pieces	Objective
Gold	1 flagship + 11 escorts	Move flagship to any edge square
Silver	20 ships	Capture the flagship

Turn Options:

• 2 moves (horizontal/vertical, any distance) — no captures
• 1 capture (1 square diagonally) — no other moves
• Moving the flagship = entire turn for Gold

Movement: Rook-like (horizontal/vertical, any distance, no jumping) Capture: 1 square diagonally only