Erase your opponent from history by killing them from two out of three time boards.

Overview

You and your opponent are rival time travelers, each claiming that you are the true inventor of time travel. To succeed at this, you need to erase your opponent from history.

The game is played through three eras: past, present, and future. To win, you need to erase your opponent from at least two of the three eras. You have multiple copies of yourself, representing you at different points of your life. You can time travel between boards, possibly creating new copies of yourself. But your opponent can do the same, so you need to kill your opponent many times before you can succeed.

The three time boards represent the same locations at different times. As such, an action you take on one board may have an impact on later boards. For example, growing a seed will cause a shrub and a tree to grow later, or moving an inanimate statue in the past means the statue also exists in its new location in the future.

Setup

The game is played on three time boards, called eras: past, present, and future. Each era is 4x4 and its spaces are numbered 1 to 16 in reading order: first row is 1 through 4, next row is 5 through 8, and so on.

Each player has 7 player pieces; these are copies of your same self.

• • Each player places 3 of their player pieces, one on each era. The white player places their pieces on space 1 of each era. The black player places their pieces on space 16 of each era.
• • The remaining 4 player pieces make up each player's supply.

Each player has a focus token, always pointing to one of the three eras. The first player has their focus token on the past era. The second player has their focus token on the future era.

There are additionally other components, depending on which chapter is being played. See #Chapters for more information.

Turn

On your turn, do the following three steps:

1. Choose any one of your copies, on the era where your focus token is on. This is your active copy.
2. Do 2 actions using the active copy. You may choose actions in any combination, including choosing the same action twice. You cannot split up these actions across multiple copies.
3. Move your focus token to a different era.
4. Check for game end.

Note that your active copy may move, and may even move to a different board. But it is still your active copy.

If you have multiple player pieces, you must choose one where you can take 2 actions if possible. If not, you choose one where you can take at least 1 action.

If none of your pieces can do any action — most likely because you have no piece at all on that era — then you forfeit steps 1 and 2, you simply move your focus token and check for game end.

Game end

You win if, at the end of your turn, there is only one (or no) era in which your opponent has copies. It doesn't matter whether the opponent still has copies in their supply.

Also, you can never lose on your own turn, since you only check for your win on your turn (and not the opponent's win). It is legal to leave yourself on just one era. Usually it is a bad idea, but if you can win on the same turn, you win before your opponent can check for winning on their next turn.

You may concede using the usual BGA feature "concede this game". Note that conceding is only available after the game reaches 50% progression.

It is also possible that the game reduces to a stalemate. BGA tries to detect this and offers an "Offer draw" button when it thinks the game is not progressing. You may agree on a draw by using the usual BGA feature "propose to abandon this game collectively".

Actions

These actions are always available. Actions may cause effects, which are automatically performed.

Action: Move

Move your active copy one space orthogonally (not diagonally) on the same era. You may choose any direction that is legal, and if you take this action multiple times, you can choose different directions.

You may not move outside the board. You may not move to a space occupied by another of your copies. However, you may move to a space occupied by an opponent's piece.

Effect: Push

When a piece moves into a space occupied by an opposing piece, the opposing piece is pushed one space in the same direction. This may cause the opposing piece to push another piece, and so on.

Effect: Squish

If, following a push, the opposing piece cannot legally occupy the next space (because e.g. it is outside the board), the opposing piece dies.

A dead copy is removed from the game permanently; it does not return to a player's supply.

Effect: Paradox

If, following a push, the opposing piece occupies a space with another opposing piece, this causes a paradox. Both opposing pieces die.

Action: Time travel forward

Move your active copy to the same space on the next era. The destination space must be empty, and your active copy cannot already be on the future era.

It is legal to time travel forward twice (from past to future), but the first action must resolve in full before you can take the second action. In particular, you cannot do this if there is something blocking your way on the present board.

Action: Time travel backward

Move your active copy to the same space on the previous era. The destination space must be empty, and your active copy cannot already be on the past era.

After that, place a copy from your supply on the space you just vacated (on the era before you time traveled backward). This represents you aging through time.

If you don't have any copies left in your supply, you can no longer time travel backward for the rest of the game.

It is legal to time travel backward twice, with the same caveats as time traveling forward. Do note that each action will cause you to place a copy from your supply. It is legal to time travel forward and then backward. (The other way around will likely not work, because time traveling backward will leave a copy of yourself, and then you cannot time travel forward as the space is occupied.)

Chapters

The game comes with 3 different modules. The rulebook introduces them in order (Chapters 1 to 3), and then introduces a way to use multiple modules at once (Chapter 4). There is also an unofficial "Chapter 0" that does not use any of the modules.

The rulebook recommends you to play Chapters 1 to 3 at least three times each, so you are familiar with the rules and the strategies, before moving on to the next one. The rulebook does not recommend playing "Chapter 0" at all, but it is there if you want to get used to the basic rules first.

Any rules about specific chapters override the defaults described above. Each module is independent; while playing Chapters 1 to 3, you do not use any component in a previous chapter, you start fresh each time.

Chapter 0: Introductory game

This chapter does not use any other module. Note that a stalemate is much more likely in this chapter.

Chapter 1: Growth

The Growth module introduces plants in the form of seeds, shrubs, and trees.

There is a shared supply containing 5 of each.

Pieces overview

Seeds do not block player pieces. A player piece may occupy the same space as a seed; when moving, pushing, and time traveling, treat these spaces as empty.

Shrubs are immovable and essentially act as walls. A player piece may not occupy the same space as a shrub, so they may not move to a shrub. If a player piece gets pushed to a shrub, they die.

Trees can be pushed; a tree topples to become a fallen tree. Read more about this below.

Fallen trees are immovable, like shrubs. Their trunk points to a space where it fell from; this is only used for the "ungrow" effect below.

Action: Plant seed

Place a seed on the current space of your active copy, or any orthogonally adjacent space. The supply must still have a seed remaining.

Effect: Grow

When a seed is placed on a space, if the same space on the next era is empty, place a shrub there.

When a shrub is placed on a space, if the same space on the next era is empty, place a tree there.

Note that if a shrub cannot grow on the present era, a tree will not grow on the future era either, even if the space is empty.

Note that a seed counts as an occupied space for the purpose of the "grow" effect.

Action: Remove seed

Remove a seed on the current space of your active copy, or any orthogonally adjacent space. Return it to the common supply.

Effect: Ungrow

When a seed is removed from a space, also remove any shrub on the same space on the next era.

When a shrub is removed from a space, also remove any tree on the same space on the next era, or any fallen tree whose trunk points to that space on the next era. (Read about fallen trees below.)

Using other modules, it's possible to remove a seed or a shrub without using the "remove seed" action. The "ungrow" effect will still apply regardless.

Effect: Topple

A tree can be pushed, so a player piece may legally move to a tree.

If a tree is pushed (e.g. by a player piece moving to it, or a player piece being pushed to it), it topples to the next space. It becomes a fallen tree, whose trunk points to the space it fell from.

If a tree topples onto a space containing a seed or a player piece, it is crushed. The player piece dies. The seed is removed.

If a tree topples onto another tree, the latter tree will also topple in the same direction.

A tree cannot topple onto a shrub or to outside the board. If this would happen, the tree does not topple and acts as an immovable object. A player piece pushed to such tree will be squished and die.

Chapter 2: Influence

The Influence module introduces statues. These are objects that can be pushed and pulled. Statues persist through time; when a statue is moved on an era, the same movement is reflected on all later eras.

During setup, a yellow statue is placed on space 7 on each board. Each player also takes 3 statues of their color into their supply.

Pieces overview

Each statue of a color represents a single statue that persists through time. At the start of the game, there is one statue already present (yellow). Each player may build a statue once per game.

Effect: Push statue

When anything moves into a space occupied by a statue, the statue is pushed one space in the same direction. This may result in additional pushes in the same era.

A moving statue can also push other objects.

If a statue cannot be pushed, it is immovable and acts like a wall. A player piece pushed to it will be squished and die.

Effect: Pull statue

When something moves (not pushed) away from a statue, it may also pull the statue. The statue is moved onto the space just vacated.

Effect: Propagate move

When a statue is moved, the same statue in the next era (if it exists) moves one space in the same direction. Note that the statue might be anywhere on the board for that era.

If a statue cannot move, it will not propagate the moving attempt to the next era.

Action: Build statue

Place a statue on a space orthogonally adjacent to your active copy. You may only do this action once per game.

Effect: Propagate build

If you place a statue on a space, also attempt to place a statue on the same space on the next era. If the space is occupied, pretend the new statue is moving onto that space from the same direction, and push anything pushable (e.g. a player piece or another statue) accordingly.

If the statue cannot push the object, what happens next depends on the game setting:

• • "Use current rule" on build statue: Use the 2023 revision. The statue is not built in the later era. This also means the build does not further propagate.
• • "Use old rule" on build statue: Use the original 2021 rule. If the statue cannot be built in that direction, it instead rebounds and tries to build on the opposite direction. For example, you are on space 7 and build a statue onto space 6. In the next era, the propagated build tries to build a statue onto space 6, coming from space 7 (i.e. any object on space 6 is pushed onto space 5). If the object is not pushable, the build rebounds instead; try to build the statue on space 7 instead, coming from space 6 (i.e. any object in space 7 is pushed onto space 8). Note that if this is successful, the build propagates further using this new direction. If both of these do not succeed, the statue is not built.

Chapter 3: Memory

The Memory module introduces elephants. They can be trained and they remember your training through time. They can also be commanded to move remotely. Elephants are also exceptionally heavy, able to trample other objects.

During setup, on each board, a dark elephant is placed on space 4 and a light elephant is placed on space 13. Each player also takes 3 hats of their color into their supply.

Pieces overview

Each elephant of a color represents a single elephant that lives old enough to span through all three eras.

An elephant can be trained by one player or the other, or wild (not trained by either player). It is impossible for an elephant to be trained by both players simultaneously; when it is trained by one player, it forgets all training from the other player.

Elephants are very heavy. They cannot be pushed by anything; they act similarly as walls outside the board. If a player piece is pushed onto an elephant, it dies.

Action: Train

Place one of your hats from your supply onto an orthogonally adjacent elephant that is not wearing one of your hats.

If the elephant is wearing an opponent's hat, return it to their supply. Therefore, an elephant can only be trained by one player at a time.

If the other elephant in the same era is wearing your hat, move that hat onto the new elephant (instead of placing one from your supply). Therefore, you may only train one elephant at a time.

You may not train an elephant that is already trained by you.

Effect: Memory

If you put your hat on an elephant, you also train the same elephant on the next era, wherever it might be. Follow the same method as above (place a hat, remove opponent's hat if any, move your hat from the other elephant if any).

Note that if the elephant in the next era is already trained by you, you're not putting a new hat on it, and the "memory" effect does not further propagate.

Action: Command

Choose the elephant wearing your hat in the current era, wherever it might be. Move it one space orthogonally.

It doesn't matter where your active copy is on the current era. But there must be one, so if you cannot choose an active copy where your focus token is, you cannot take the "command" action, even if an elephant in that era happens to be wearing your hat.

Effect: Trample

If an elephant moves onto a player piece, the copy is trampled and dies. Note that it is not pushed away, it simply dies.

Chapter 4: Convergence

This chapter introduces rules to combine multiple modules together.

The game options let you choose one of four variants of Chapter 4. You can choose to mix any 2 specific modules, or you may let BGA choose a random selection of 2 out of the 3 modules.

This chapter lists additional clarifications of how pieces from different modules interact.

If multiple effects would happen together, resolve them in the following order: remove objects, then place objects, then move objects.

Growth + Influence

• • A space with a seed counts as occupied, and you cannot build a statue there.
• • However, if a statue propagate-builds onto a space containing a seed, remove the seed (and perform ungrow effects).
• • If a statue moves onto a seed, remove the seed.
• • Statues cannot be moved onto shrubs or fallen trees, because they are immovable.
• • Statues can be moved onto trees. This topples the tree.
• • Toppled trees can move onto statues. This pushes the statue.

Growth + Memory

• • Elephants can move onto seeds, shrubs, and fallen trees. This tramples the object; the object is removed.
• • Elephants can move onto trees. This topples the tree.
• • Nothing can move onto elephants. In particular, trees cannot topple onto elephants.

Influence + Memory

• • Elephants can move onto statues. This pushes the statue.
• • Elephants can also pull statues, because they are moving.
• • You cannot build a statue on elephants.
• • Nothing can move onto elephants. In particular, statues cannot be pushed onto elephants. If this is the result of a propagate-build, the statue might rebound away (if using old rule).