Momentum

Overview

Momentum is a two-player abstract strategy game played on a 7x7 board with glass marbles. Players alternate placing marbles, and each placement transfers momentum through adjacent lines of marbles, pushing the last marble in each line one space away. Marbles pushed off the board edge are returned to their owner. The goal is to be the first player to have all 8 of your marbles on the board simultaneously.

Components

• 1 game board (7x7 grid)
• 8 red marbles
• 8 blue marbles

Setup

1. Place the empty board between the two players.
2. Red takes 8 red marbles; Blue takes 8 blue marbles.
3. Red places first.

Turn Structure

Players alternate turns. On your turn:

1. Place 1 marble from your supply onto any unoccupied space on the board.
2. Resolve momentum: the placed marble pushes the last marble in each contiguous line (up to 8 directions) one space away from the placed marble.

Pie Rule: On the second player’s first turn only, they may either place a marble normally or swap the first player’s marble with one of their own.

Actions

Placing a Marble

Drop one marble onto any empty space on the 7x7 board.

Momentum Transfer

When a marble is placed, its “momentum” transfers in all 8 directions (4 orthogonal + 4 diagonal) through adjacent contiguous lines of marbles (regardless of color). The last marble at the end of each such line is pushed one cell away from the placed marble.

• If the pushed marble moves into an occupied space, nothing happens (it stays).
• If the pushed marble moves off the edge of the board, it “falls off” and is returned to its owner’s supply.

Scoring / Victory Conditions

Win: Have all 8 of your marbles on the board after your turn. Since each placement can push marbles off, you must manage the board state so all your marbles remain while potentially pushing opponents’ marbles off.

Special Rules & Edge Cases

• Momentum transfers through marbles of BOTH colors – all marbles in a line transmit the push.
• Multiple marbles can be pushed off in a single placement (one per direction).
• A marble pushed off the board returns to its owner’s supply; that player must re-place it on a future turn.
• The Pie Rule prevents first-player advantage.

Player Reference

Phase	Action
Place	Put 1 marble on any empty space
Momentum	Push last marble in each contiguous line 1 space away
Edge	Pushed-off marbles return to owner
Win	All 8 of your marbles on the board after your turn