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Vacuum v5.6.16 Manual

Vacuum v5.6.16 Manual

This manual describes how to play Vacuum v5.6.16 and how to use the interface. It is written from the current game code and current tool-tip text, not from older rule drafts.

Vacuum is a turn-based abstract strategy game for 2 to 4 players. Players build pressure with pebbles, compress pressure into stones, collide stones into boulders, and reshape the board edge while trying to keep enough final-move options alive to stay in the game.

Table of Contents

Learning the game

Interface

Board and pieces

Actions by stage

Reference

Quick Start

  1. Open Vacuum.html.
  2. Choose 2 Players, 3 Players, or 4 Players in the new-game dialog. See Starting a Game.
  3. On your turn, use a lit button in the right panel. Buttons that are not legal right now are disabled. See Action Buttons.
  4. Actions are organized by stage:
  5. You must finish the turn with one Final Action, then press Commit.
  6. Hover board squares to read pressure values in the left panel. See Diagnostics.
  7. Hover or focus action buttons to read the left-panel Tool Tips.
  8. Right-click anywhere in the app for Open Manual, Save Game, and Load Game.

The most important beginner rule is this: buttons tell you what is currently legal. If a button is dark/disabled, that action has no legal use right now or you have already advanced past its stage.

Objective

The goal is to be the last active player remaining.

Players can leave the game by:

When all but one player are eliminated, the remaining player wins.

See Winning, Losing, and Elimination for the full details.

Core Idea

Vacuum is about pressure and timing.

You create and move pebbles, compress pebbles into stones, collide stones into boulders, and use pressure to win fights. The game is not just about having pieces; it is about where those pieces are and how much pressure they project around a target square.

The main strategic loop is:

The board can shift from quiet positioning to sudden collapse very quickly. A single point of pressure imbalance can open a line, and a prepared boulder road can turn a slow defensive anchor into a fast crisis response.

Starting a Game

When no saved game is loaded, Vacuum opens a New game modal and asks for the number of players.

You may choose:

The game starts with an empty board. There are no starting pieces. Players must create their first material through actions such as Vacuum Move, Perimeter Move, and later Extend Supply Chain.

Player 1 starts.

See also:

The Three Panels

The interface has three main areas in landscape view. In portrait view the same areas are rearranged so the board remains large and playable.

Left / top information panel

In landscape view, this is the left panel. In portrait view, it becomes the top information shelf.

The information panel contains:

Center panel

The center panel contains the board.

Hovering board squares updates Diagnostics. Clicking board squares selects sources and targets for actions. Many actions also support drag-and-release targeting. See Clicking, Dragging, and Source Highlighting.

Right / bottom command panel

In landscape view, this is the right panel. In portrait view, it becomes a bottom command tray.

The command panel contains:

Only currently legal actions are lit and enabled.

Portrait Layout

When the browser window is tall and narrow, Vacuum switches to portrait layout automatically.

Portrait layout uses:

In the Controls / Stage 3 column, Undo and Commit stay on the same row, Stage 3 actions sit below them, and Resign is separated below with extra space.

The Log/Info toggle still works in portrait. Static status and diagnostics stay visible on the left side of the top shelf while the right side switches between Tool Tips and the move log.

Action Buttons

The right panel actions are organized by stage. A button lights when the current player may legally use that action at the current stage of the turn. Disabled buttons are not available right now.

Hovering, focusing, or clicking a button updates the left-panel Tool Tips. Selecting an action changes the status text and prepares the board for source and target selection.

See also Stage 1: Movement Actions, Stage 2: Core Actions, and Stage 3: Final Actions.

Title, Turn Number, and Move Number

The title line shows something like:

Vacuum v5.6.16 | Turn #14 | Move #3

Version

The version number identifies the current build. The full manual can also be opened from the right-click menu.

Turn number

The turn number counts successful Commit presses. It is not tied to one color. It is the total number of committed player turns so far.

Move number

The move number is the current turn’s undo snapshot count. In practical terms, it is the number of saved move segments in the current turn.

Most completed actions add one undo snapshot. Supply Chain and Boulder Chain can add multiple snapshots because they undo one segment at a time.

See also:

Status

The Status box in the left panel gives short messages about the current action.

It tells you things like:

For full action rules, use Tool Tips and this manual.

Tool Tips

The Tool Tips box in the left panel shows player-facing help for the button you hover, focus, or click.

Tool tips are meant to explain the action in human terms: what you are trying to do, what kind of source/target is needed, and what stage you go to afterward.

Use tool tips while playing. They are especially useful for:

Diagnostics

Hovering a board square updates the Diagnostics box.

Diagnostics show:

The pressure readout is target-centered. This matters because Pebble War and Boulder attack compare pressure around the target square, not around the attacking source.

See Pressure Value for the calculation.

Right-Click Menu, Manual, Save, and Load

Right-click anywhere in the app to open the custom Vacuum menu.

The menu currently contains:

Open Manual

Open Manual opens Vacuum_manual.html in a new browser tab. The manual is the full rules and interface reference. The left-panel Tool Tips are shorter reminders for the action you are currently looking at.

Save Game

Save Game creates a .png image of the current board position. The image works as a visual thumbnail so you can recognize a save file by looking at it.

The full Vacuum save JSON is embedded inside the PNG. That means the PNG can be loaded later through Load Game.

The save includes:

The older plain JSON save command is no longer shown in the right-click menu. Save Game now means the visual PNG save.

Load Game

Load Game opens a file picker. Choose a compatible Vacuum save .png file. Older .vacuum.json and .json saves may still load for backward compatibility.

Loading replaces the current board state. The loaded game also becomes the current autosaved game, so refreshing or reopening the page continues from the loaded position.

See also:

Phase Two Online Rooms

Vacuum v5.6.16 is part of the Phase Two online-play line. Local play remains intact, online room sync is available, and this build also includes local rules and interface refinements.

v5.6.16 adds: Online Room Seats panel. Players may claim Red, Gold, Green, or White seats in an online room, leave a seat, and see shared seat status across connected clients. Free Table Mode remains the default in this foundation build; seat claiming does not yet restrict who can move.

Earlier v5.6 line fixes retained: Pebble Attack outlines and moves exactly the selected attacking pebble count. Teleport recognizes any active piece of your color on a usable pedestal, including stones and boulders, not only pebbles.

Online rooms require the included Cloudflare Worker and Durable Object files. If the game is opened directly from disk as a local file, online room commands report that the hosted version is required.

The first online model is intentionally simple: the browser sends the full saved game state after moves, and the room broadcasts the latest state to connected players. This is good enough for the first internet prototype and avoids touching the Phase One rules engine.

While connected, the browser sends small heartbeat pings to keep idle rooms alive. If the connection still drops, the game automatically tries to reconnect to the same room and reloads the room's latest saved board state.

Resizable Information Panel

The information panel can be resized.

In landscape view, drag the handle on the right edge of the left information panel:

In portrait view, drag the horizontal handle at the bottom of the top information shelf:

When the pointer is in the resize zone, the cursor changes to show the resize direction.

Clicking, Dragging, and Source Highlighting

Most source-and-target actions support two control styles.

Click-click

  1. Click the action button.
  2. Click a valid source.
  3. Click a valid target.

Drag-release

  1. Click the action button.
  2. Press down on a valid source.
  3. Drag to a target.
  4. Release.

The game treats pressing down on a valid source as source selection. You do not need to first click the source and then start dragging from it.

Source highlighting

When a source is selected, its square pulses green. The green source highlight clears when:

Count cycling

Some pebble actions let you click the same source repeatedly to cycle the number of pebbles used.

Count cycling applies to:

Undo and Commit

Undo

Undo reverses moves within the current turn.

Most actions undo as one complete action.

Two actions are segment-based:

Those actions can contain several linked steps, so undo backs up one link at a time.

Undo is only for the current turn. Once you press Commit, the turn is passed and that committed turn cannot be undone.

Commit

Commit ends the current player’s turn after a Final Action has been completed.

Commit becomes available only after Stage 3 resolves and the turn reaches the commit state.

Commit cannot be undone.

When you commit:

Board Overview

The board is a 12 × 12 grid with a shaped playable area.

There are four kinds of terrain:

Only non-barren tiles are playable.

Rows and columns shown in diagnostics are zero-based: row 0 through row 11, column 0 through column 11.

Tile Types

Barren / void

Barren space is not playable.

Pieces generally cannot move into barren space. Perimeter Move is the exception: it slides a perimeter tile outward into adjacent barren space, leaving barren space in the tile’s wake.

Barren space has pressure multiplier 0.

Perimeter tiles

Perimeter tiles are the colored edge tiles around the board. They are playable.

Perimeter tiles have pressure multiplier 1.

Perimeter tiles are also used by Perimeter Move.

Board tiles

Board tiles are the main interior playable tiles.

Board tiles have pressure multiplier 2.

Pedestal tiles

Pedestals are the four special inner-corner tiles.

Pedestals have pressure multiplier 4.

Pedestals are used by Teleport. They are also powerful pressure anchors because of the high multiplier.

Player Colors and Perimeters

Vacuum supports up to four players.

Player Color Perimeter region
Player 1 Red Upper-left perimeter
Player 2 Gold Lower-left perimeter
Player 3 Green Lower-right perimeter
Player 4 White Upper-right perimeter

In games with fewer than four players, unused perimeter colors are considered unowned for Perimeter Move. For example, in a two-player game, green and white perimeter tiles are not owned by an active player.

Home Pedestals

Each player has a home pedestal. Home pedestals are mainly relevant to Cast Stone, because a stone that travels the full cast distance may hook one square toward its owner’s pedestal.

Player Color Home pedestal
Player 1 Red Upper-left pedestal
Player 2 Gold Lower-left pedestal
Player 3 Green Lower-right pedestal
Player 4 White Upper-right pedestal

See Cast Stone: Hook for the exact rule.

Pieces

There are three active piece types:

There can also be Neutral Pieces after resignation.

Pebbles

Pebbles are the basic material of the game.

A pebble has base value 1 before terrain multiplier.

A tile can hold up to 4 pebbles total.

Pebbles are used for:

Pebbles are fragile but flexible. They are also the only piece type that can stack.

Stones

Stones are compressed force.

A stone has base value 3 before terrain multiplier.

A stone is created by Stone Creation. Stones can then be moved with Cast Stone.

Stones are not just stronger pebbles. They do not use Supply Chain, Pebble War, or Reduction Attack. Their main destiny is to become or support boulders.

A stone can be removed by:

Boulders

Boulders are maximum-density pieces.

A boulder has base value 9 before terrain multiplier.

Boulders are formed when a cast stone strikes a non-neutral stone. See Cast Stone.

Boulders are slow unless prepared. A normal Boulder Move moves one adjacent square. A Boulder Chain lets a boulder burn through your own pebble road for extra movement.

A boulder can attack opponent pebbles, stones, or boulders through Boulder attack if its owner wins the target-centered Pressure Value comparison.

A boulder can be removed by a successful enemy Boulder attack.

Neutral Pieces

When a player resigns while two or more players remain, that player’s pieces stay on the board as neutral obstacles.

Neutral pieces:

Neutral pieces help preserve the shape and consequences of the resigned player’s position without allowing anyone to command those pieces.

See Resignation.

Pressure Value

Pressure value is the game’s combat math.

Pressure is always measured centered on a target square.

To calculate a player’s pressure centered on a square:

  1. Look at the center square and the eight neighboring squares around it.
  2. For each square in that 3 × 3 area, count that player’s pieces on that square:
    • Pebble = 1 base value.
    • Stone = 3 base value.
    • Boulder = 9 base value.
  3. Multiply each square’s piece base value by that square’s terrain multiplier:
    • Perimeter = ×1.
    • Board = ×2.
    • Pedestal = ×4.
    • Barren = ×0.
  4. Add the results.

Example: a boulder on a pedestal contributes 9 × 4 = 36 pressure from that square.

Pressure is used by:

Pressure is not just material count. Terrain matters a lot.

Turn Structure

Each turn begins at Stage 1 and eventually ends with Commit.

There are three action stages plus the commit state:

  1. Stage 1: Movement Actions
  2. Stage 2: Core Actions
  3. Stage 3: Final Actions
  4. Commit

You are not forced to use every stage. You may choose any lit action in your current stage or a later stage. Choosing a later-stage action skips the earlier unused stages for that turn.

Once an action advances you to a later stage, you cannot go back to earlier stages unless you use Undo.

Stage 1 result

Every Stage 1 action advances to Stage 2 after resolving.

Stage 1 actions:

Stage 2 result

Stage 2 actions behave differently:

Because Stone Creation, Pebble War, and Teleport keep you in Stage 2, you may be able to perform multiple core actions in one turn if legal.

Stage 3 result

Stage 3 actions are final actions.

After Vacuum Move or Perimeter Move, you go to Commit.

Stage 1: Movement Actions

Stage 1 is about movement, positioning, material growth through extension, and high-impact relocation.

Every Stage 1 action advances to Stage 2.

Stage 1 actions are:

Pebble Entrench

Back to Stage 1 · See Pebbles

Pebble Entrench adds one pebble to one of your existing pebble stacks. It is a compact reinforcement action rather than a movement action.

Source

Choose a playable tile containing your pebbles.

The tile must contain:

A four-pebble stack cannot entrench. A tile blocked by neutral pebbles, a stone, or a boulder is not a legal entrench target.

Target

Pebble Entrench has no separate destination tile. The chosen source tile is also the target.

Result

One new pebble of your color is added to the chosen tile.

After Pebble Entrench resolves, you go to Stage 2.

Pebble Retreat

Back to Stage 1 · See Pebbles

Pebble Retreat moves a whole pebble unit exactly two squares without moving closer to any active opponent piece.

Source

Choose a tile containing your pebbles.

The whole movable pebble unit retreats together.

Target

The target must be:

A king-step uses Chebyshev distance: horizontal, vertical, and diagonal steps all count as one.

Path

At least one middle square must allow the retreat path.

The middle square may be:

The middle square blocks retreat if it contains:

No moving closer

The retreat destination cannot be closer to any active opponent piece than the source was.

Result

The pebble unit moves to the target.

After Pebble Retreat resolves, you go to Stage 2.

Extend Supply Chain

Back to Stage 1 · See Supply Chain

Extend Supply Chain creates one new pebble from a two-pebble line.

This action is important because it makes Stage 1 an economy choice: using another Stage 1 action means you are not using Stage 1 to create a new pebble.

Required shape

You need two touching single pebbles of your color.

The selected source must be one of those single pebbles.

Target

The target must be:

In other words, the move extends a two-pebble line into a three-pebble line.

Result

A new pebble of your color is created on the target.

After Extend Supply Chain resolves, you go to Stage 2.

Cast Stone

Back to Stage 1 · See Stones · See Boulders

Cast Stone throws one of your stones in a straight line.

Source

Choose one of your stones.

Direction

Choose one of eight straight directions:

The clicked or dragged target only chooses the direction. The stone may stop before reaching that exact square.

Cast distance

The stone travels up to three squares in the chosen direction.

It stops before normal blockers:

Boulder collision

If the moving stone hits a non-neutral stone, both stones become one boulder on the struck stone’s square.

The struck stone may be:

The resulting boulder belongs to the player who cast the moving stone.

Hook

If the stone reaches the full third square without stopping or forming a boulder, it may hook one square toward its owner’s Home Pedestal.

The hook only happens if the home pedestal is in a straight row, column, or diagonal from that third square.

The hook follows the same collision rules as the main cast:

Result

The stone either moves, forms a boulder, or stops before obstruction.

After Cast Stone resolves, you go to Stage 2.

Boulder Move

Back to Stage 1 · See Boulders · See Pressure Value

Boulder Move gives a boulder four possible behaviors:

Normal boulder movement

A boulder may move one square in any direction to an empty playable square.

After a normal empty-square Boulder Move, you go to Stage 2.

Boulder attack

A boulder may move one square into an adjacent enemy-occupied square if its owner wins the target-centered Pressure Value comparison.

A boulder can attack opponent:

The attack target cannot contain neutral pieces or your own pieces.

The pressure comparison is centered on the target square. Your pressure must be strictly greater than the defender’s pressure for your boulder to survive and take the target.

If the attack succeeds:

Boulder sacrifice

If your boulder moves against an adjacent enemy boulder and does not win the pressure comparison, the move becomes a sacrifice instead of a failed attack.

Boulder sacrifice applies only to boulder against enemy boulder. It does not let a boulder sacrifice against pebbles or stones, and it cannot happen during Boulder Chain.

Boulder Chain

A boulder may move onto an adjacent square containing only your own pebbles.

Those pebbles are consumed. The boulder moves onto that square and enters Boulder Chain mode.

Boulder Chain represents preparation: a pebble road, supply line, or work crew being spent to drag or shove the boulder where it is desperately needed.

While Boulder Chain is active:

Click Exit Boulder Chain when you are done. Exiting Boulder Chain advances to Stage 2.

Undo during Boulder Chain backs up one consumed segment at a time. See Undo and Commit.

Pebble Attack

Back to Stage 1 · See Pressure Value

Pebble Attack is a once-per-turn Stage 1 pressure strike. It lets a selected number of pebbles attack an adjacent enemy-occupied square if your target-centered pressure is strictly greater.

Source

Choose one of your pebble stacks. Click the source again to cycle how many pebbles will attack.

Target

The target must be adjacent and must contain an active enemy piece. Pebble Attack may target pebbles, stones, or boulders.

Pressure check

The pressure comparison is centered on the target square. Your attacking pressure must be strictly greater than the defender’s pressure. Equal pressure is not enough and does not cause mutual destruction.

Result

Teleport

Back to Stage 2 · See Pedestal Tiles

Teleport swaps the contents of two pedestals.

Source

The source must be a pedestal containing one of your active pieces: pebble, stone, or boulder.

Neutral pieces block Teleport. A pedestal containing only neutral pieces, or only enemy pieces, is not a valid source.

The source pedestal cannot be on teleport cooldown.

Target

The target may be any pedestal, including the same pedestal.

The target pedestal cannot:

Result

The contents of the source and target pedestals are swapped.

The involved pedestals go on teleport cooldown for the teleporting player.

Cooldowns expire at the beginning of that same player’s next turn.

After Teleport resolves, you remain in Stage 2.

Stage 2: Core Actions

Stage 2 is where most tactical and economic work happens.

Stage 2 actions are:

Stage 2 actions do not all advance the turn the same way.

Action Stage result
Supply Chain Continues in Stage 2, or exits to Stage 3 if moved into empty space
Reduction Attack Advances to Stage 3
Stone Creation Stays in Stage 2
Pebble War Stays in Stage 2

Because Stone Creation and Pebble War leave you in Stage 2, one turn can sometimes contain several core actions.

Supply Chain

Back to Stage 2 · See Extend Supply Chain

Supply Chain moves pebbles through connected friendly pebble positions.

It is a Stage 2 action.

Source

Choose a tile containing your pebbles.

Click the same source to cycle how many pebbles move.

While Supply Chain is active, you can also click another valid source to switch to that source without exiting and re-entering the action.

Chain movement onto friendly pebbles

You may move selected pebbles to an adjacent playable tile containing your pebbles if there is enough room on the target.

The tile limit is still 4 pebbles total.

When you move onto your own occupied tile:

Empty-square exit

You may move selected pebbles into an adjacent empty playable square.

This exits Supply Chain and advances to Stage 3.

Important restriction: when exiting into an empty square, you must leave at least one of your pebbles behind on the source.

That means:

This keeps Supply Chain from becoming a fake extra movement action. It must still preserve the feeling of extending a chain.

Exit button

Click Exit Supply Chain to stop chaining without moving into an empty square.

Manual exit leaves you in Stage 2.

Undo

Supply Chain stores undo snapshots per link. Undo reverses one chain segment at a time.

Reduction Attack

Back to Stage 2 · See Pebbles

Reduction Attack spends your pebbles to remove the same number of adjacent opponent pebbles.

Both sides lose the selected number of pebbles.

Source

Choose a tile containing your pebbles.

Click the source repeatedly to cycle the attack count.

Target

The target must be an adjacent playable tile containing active opponent pebbles.

Neutral pebbles are not valid targets.

Count limits

Let:

The selected attack count must follow these limits:

Examples:

Result

The selected number of your pebbles is removed from the source. The same number of opponent pebbles is removed from the target.

After Reduction Attack resolves, you go to Stage 3.

Stone Creation

Back to Stage 2 · See Stones

Stone Creation compresses surrounding pebble pressure into one stone.

This action stays in Stage 2 after resolving.

Target

The target must be:

Neighbor area

Look at the eight neighboring squares around the target.

Only pebbles matter for the creation test. Stones, boulders, and terrain pressure do not count for the creation test.

Side coverage requirement

Your neighboring pebbles must cover at least three neighboring sides of the target.

The four sides are:

Orthogonal pebbles cover their obvious side.

Diagonal pebbles can help cover one of the two sides they touch.

A straight three-pebble line does not satisfy the spirit of this rule by itself. The formation must meaningfully surround the target from at least three sides, not merely line up through it.

Pebble dominance requirement

Your neighboring pebble count must be at least three more than all other neighboring pebbles combined.

Formula:

your neighboring pebbles >= other neighboring pebbles + 3

Other neighboring pebbles include all other active players’ pebbles and neutral pebbles.

Result

If Stone Creation succeeds:

Pebble War

Back to Stage 2 · See Pressure Value

Pebble War moves a whole pebble unit into an adjacent opponent pebble unit if your target-centered pressure wins.

Pebble War is a repeatable Stage 2 mode. After a successful attack, the attacking unit becomes the next source if it still has legal adjacent targets. You can keep gobbling through a chain, exit Pebble War, or choose another legal action.

Source

Choose one of your pebble units.

The whole unit attacks together. You do not choose a partial count.

Target

The target must be adjacent and must contain active opponent pebbles.

Neutral pebbles are not valid Pebble War targets.

Pressure check

Compare pressure values centered on the target square.

Only the attacking player and the chosen defending player matter for this comparison.

Your pressure must be strictly greater than the defender’s pressure.

See Pressure Value.

Result

If Pebble War succeeds:

In multiplayer edge cases, third-party pebbles on the target do not help either side in the pressure comparison, but they still occupy space and can prevent the attacking unit from fitting.

Stage 3: Final Actions

Stage 3 is the final-action stage.

A turn must eventually complete one final action before Commit becomes available.

Stage 3 actions are:

After either final action resolves, you go to Commit.

Vacuum Move

Back to Stage 3

Vacuum Move creates one pebble in an empty vacuum space.

Shortcut: if no action button is selected, clicking a legal Vacuum Move target automatically performs Vacuum Move.

Target

The target must be:

Vacuum area

A valid vacuum area is a 3 × 3 area where:

The target does not have to be the center of the 3 × 3 area. It only has to belong to at least one valid empty 3 × 3 area.

Result

One pebble of your color is created on the target.

After Vacuum Move resolves, you go to Commit.

Perimeter Move

Back to Stage 3 · See Perimeter Tiles

Perimeter Move slides an eligible perimeter tile outward into an adjacent barren space.

A barren space is left in the tile’s wake, changing the shape of the board edge.

Source

The source must be one of these:

The source cannot contain neutral pieces.

The source must orthogonally touch a barren space. Diagonal contact is not enough.

Target

The target must be a directly attached barren square.

Only orthogonal barren spaces count.

Result

The selected perimeter tile slides into the barren space and carries its contents with it.

The old source square becomes barren.

After Perimeter Move resolves, you go to Commit.

Winning, Losing, and Elimination

Players can leave the game in several ways.

Resignation

A player may press RESIGN and confirm.

If only one player remains after the resignation, that player wins.

If two or more players remain, the resigning player is eliminated and their pieces become Neutral Pieces. Play continues with the next remaining player.

No-final-move elimination

At the beginning of a player’s turn, the game checks whether that player has any legal final action.

Final actions are:

If the player has no legal Vacuum Move and no legal Perimeter Move, that player is eliminated.

If more than one player remains, the game advances to the next remaining player and checks again as needed.

Stone-era piece loss

A player does not lose merely because they temporarily have no pieces before they have ever created a stone.

Once a player successfully creates their first stone with Stone Creation, that player enters the stone era.

After that point, if all of that player’s pieces are removed from the board, that player is eliminated.

Pieces counted for this rule include:

Winning

When only one active player remains, that player wins.

Action Summary Table

Action Stage Main purpose Stage result
Pebble Entrench 1 Add one pebble to a 1–3 pebble stack Stage 2
Pebble Retreat 1 Move a whole pebble unit exactly two squares away from danger Stage 2
Extend Supply Chain 1 Create a new pebble from a two-single-pebble line Stage 2
Cast Stone 1 Throw a stone up to three squares, possibly forming a boulder Stage 2
Boulder Move 1 Move, attack, or burn pebble road with a boulder Stage 2 after exiting/finishing
Teleport 1 Swap contents between pedestals Stage 2
Supply Chain 2 Move pebbles through friendly chain positions Stage 2 or Stage 3
Reduction Attack 2 Trade your pebbles to reduce enemy pebbles Stage 3
Stone Creation 2 Compress surrounding pebbles into a stone Stay Stage 2
Pebble War 2 Use pressure to move a pebble unit into an enemy pebble unit Stay Stage 2
Vacuum Move 3 Create a pebble in an empty vacuum space Commit
Perimeter Move 3 Slide perimeter tile into barren space Commit

What Removes What

Attacker / process Can remove
Reduction Attack Opponent pebbles
Pebble War Opponent pebble units
Stone Creation Your own neighboring pebbles, by compressing them into a stone
Cast Stone Stones, by converting two non-neutral stones into one boulder
Boulder attack Opponent pebbles, stones, or boulders, if pressure wins
Boulder Chain Your own pebbles, consumed as prepared road
Resignation Does not remove pieces if the game continues; pieces become neutral

Pebbles can be taken by pebbles or boulders.

Stones can be turned into boulders or taken by boulders.

Boulders can be taken by boulders.

Common Tactical Ideas

Extend is economy

Extend Supply Chain creates material in Stage 1. Any other Stage 1 action means you are giving up that chance to create a pebble this turn.

This makes Stage 1 a real choice: grow, reposition, retreat, teleport, cast, or move a boulder.

Pressure fields matter more than raw pieces

Because pressure uses terrain multipliers and a target-centered 3 × 3 area, the same piece can be weak on one tile and decisive on another.

Use Diagnostics to read pressure before committing to Pebble War or Boulder attack.

Boulders are anchors until fed

A boulder normally moves only one square. It can hold a front line, but it can also become stranded.

Boulder Chain lets you build pebble runways and consume them for emergency boulder movement. This is powerful, but expensive: the runway is gone afterward.

Supply lines are strength and vulnerability

Supply Chain lets you reorganize pebbles and extend into new space. But a thin line can also become a weakness if an opponent breaks it with Pebble War or boulder pressure.

Pebble War can detonate a quiet position

Because Pebble War stays in Stage 2, one won pressure fight can open another. A long period of positioning can suddenly become a chain of captures if a front line has a pressure seam.

Perimeter Move changes future space

Perimeter Move is not just a tile slide. It reshapes the edge of the board and can change future Vacuum Move, pressure, and movement possibilities.

Glossary

Active player

A player still in the game and not eliminated.

Adjacent

One square away horizontally, vertically, or diagonally, unless a rule specifically says orthogonal.

Barren

Non-playable space. See Barren / void.

Boulder

A high-density piece worth base 9 before terrain multiplier. See Boulders.

Boulder Chain

A mode inside Boulder Move where a boulder consumes adjacent own pebbles as prepared road.

Commit

The irreversible action that ends the turn after a final action. See Undo and Commit.

Final Action

A Stage 3 action: Vacuum Move or Perimeter Move.

Home pedestal

A player’s associated pedestal corner. See Home Pedestals.

Neutral

Pieces belonging to an eliminated resigned player. They remain as obstacles. See Neutral Pieces.

Pebble

The basic stackable piece, worth base 1 before terrain multiplier. See Pebbles.

Pressure

Target-centered value used by Pebble War, Boulder attack, and Diagnostics. See Pressure Value.

Source

The starting square selected for an action.

Stage

A part of the turn structure. See Turn Structure.

Stone

A compressed piece worth base 3 before terrain multiplier. See Stones.

Stone era

The state a player enters after creating their first stone. From then on, having no pieces means elimination. See Stone-era piece loss.

Target

The destination or affected square selected for an action.

Vacuum space

An empty playable target contained in a valid empty 3 × 3 area. See Vacuum Move.

Rule Cross-Links

Room launcher and account shell

Vacuum v5.6.16 begins separating the online table from the board game. The account gate, room launcher, and game board now have separate files.

The account shell is not real server authentication yet. It gives the browser a stable identity so a room can remember who claimed which seat after refresh or reconnect.