The game board for Twilight Imperium is formed using modular system tiles. Each tile represents a single system in the galaxy, which may contain one or more planets or other celestial bodies.
Systems[]
Players place system tiles during setup to create the game board. The back of each system tile is colored, indicating systems with planets (blue), faction home planets (green), and anomalies or empty space (red). Anomalies and empty space may have no planets, but are still "systems" for all game purposes.
Note: Double-sided tiles that have lines crossing from one edge to another are hyperlane tiles. Hyperlane tiles are not systems.
Placing Units on a System Tile[]
When a unit is placed in a system, it is placed in one of two areas on the tile. Structures and ground forces are usually placed on planets, while ships are placed in space—the star-filled area surrounding the planets. Any area on a system tile that is not a planet is called the "space area."
Adjacency[]
Two system tiles are adjacent to each other if any of the tiles’ sides are touching each other. A system that has a wormhole is treated as being adjacent to any system that has a matching wormhole. A system is not adjacent to itself, but a planet is treated as being adjacent to the system that contains that planet.
Systems that are connected by lines drawn across one or more hyperlane tiles are adjacent for all purposes.
Planets[]
As players move about the galaxy and expand their empire beyond their home systems, they will gain control of new planets.
When a player gains control of a planet, they take that planet’s card and place it facedown in their play area. The planet card is taken from either the deck of planet cards or from the player who controlled it previously. Each planet card displays two values: resources on the left in yellow and influence on the right in blue. Players spend resources to acquire new units and technologies. Players spend influence to gain command tokens and to vote during the agenda phase.
If a player ever controls a planet but has no units on that planet, that player places one of the control tokens that matches their faction on that planet to mark that they control it.
Planet Traits[]
Planets outside of home systems have a planet trait. There are three types of planet traits: Cultural, Hazardous, and Industrial. Planet Traits are mainly used to for scoring specific objectives (e.g. "Control 4 Cultural planets"), but also provide thematic flavor to the planet's characteristics. Hazardous planets typically have more resources and less influence, while Cultural planets typically have more influence and fewer resources.
In the Prophecy of Kings expansion, a planet's trait corresponds to the exploration deck a player draws from after exploring the planet.
Technology Specialty[]
Some planets have a technology specialty, marked by the symbol for either green, blue, yellow or red technology. A player that has control of one or more of these planets may exhaust them to satisfy a prerequisite when researching technology (i.e. they can be used as 'technology skips'). A player must choose whether to exhaust the planet for technology or for its resources/influence. They may not do both in the same round.
Mecatol Rex[]
Mecatol Rex Tile
"Of all the planets in the galaxy, no planet was more war-torn than Mecatol Rex. Over the course of only a few years, the planet’s ecology was ravaged by bombardments, its population nearly wiped out, and its green fields blasted into a toxic wasteland."
Mecatol Rex is the planet placed in the center of the game board during setup.
During setup, the Custodians Token is placed on Mecatol Rex. This token prevents a player from committing ground forces to land on the planet unless they spend six influence to remove the token.
Once a player does remove the Custodians Token, they place it in their play area and gain one victory point. Since the galactic council can now convene on Mecatol Rex, the agenda phase is added as the last phase of each game round.
| Planet | Trait | Resources | Influence | Flavor Text |
|---|---|---|---|---|
| Mecatol Rex | - | 1 | 6 | Once a splendid place, now a sad devastated wasteland. Only the radiation-shielded Mecatol city, the seat of the powerful Galactic Council, remains habitable. |
Home Systems[]
Each player begins the game with their units on a system tile with planet(s) unique to their chosen faction, known as their home system. Home system tiles are differentiated with green-colored backs, and their corresponding faction's symbol in one corner.
See: Home System for a detailed list of all factions' home systems.
Planet Systems[]
Ground forces and structures are usually placed on planets.
See Planet Systems for a detailed list of all non-home, non-mecatol systems that contain planets
Legendary Planets[]
Legendary planets are indicated by the following symbol: 
Legendary planets are notable as each has an associated legendary planet ability card. Furthermore, control of legendary planets is essential for some objectives.
- When a player takes control of a legendary planet, they also place its legendary planet ability card in their play area.
- If a player gains control of a legendary planet ability card from the deck, it is received readied.
- If a player gains control of an exhausted legendary planet ability card (e.g. taking it over from another player), it remains exhausted
- If a legendary planet’s planet card is purged, its corresponding legendary planet ability card is also purged
Prophecy of Kings Expansion[]
The Expansion introduced 4 legendary planets
- Hope's End and Primor are acquired by taking control of their systems as usual.
- Mallice is acquired by taking control of the Wormhole Nexus (See below).
- Mirage is Placed in a Frontier System by use of the Mirage Frontier Card; its details are shown below:
| Planet | Trait | Resources | Influence | Ability | Flavor Text |
|---|---|---|---|---|---|
| Hope's End | Hazardous | 3 | 0 | Imperial Arms Vault
You may exhaust this card at the end of your turn to place 1 mech from your reinforcements on any planet you control, or draw 1 action card |
Buried in the Ichal Nebula. The Lazax used the toxic wildlife and fierce aurora storms to train their troops. Even now, volatile weapon caches remain hidden beneath its sands. |
| Primor | Cultural | 2 | 1 | The Atrament
You may exhaust this card at the end of your turn to place up to 2 infantry from your reinforcements on any planet you control |
Large temperate world. Site of several pitched battles during the Twilight Wars due to valuable osmium deposits and a well- educated populace |
| Mallice | Cultural | 0 | 3 | Exterrix Headquarters
You may exhaust this card at the end of your turn to gain 2 trade goods or convert all of your commodities into trade goods |
Trapped in a space believed to be beyond our universe, a shimmering world of strange energies and disconcerting warping of physical laws sitting at the heart of a strategically vital wormhole nexus |
| Mirage | Cultural | 1 | 2 | Mirage Flight Academy
You may exhaust this card at the end of your turn to place up to 2 fighters from your reinforcements in any system that contains 1 or more of your ships |
Exists on no known charts and appears deserted to those who stumble across it. However, secretive local live in cloaked cities heavily defended by swarms of starfighters. |
The Codex[]
Volume II: Affinity[]
The Codex II: Affinity relic Nano-Forge allows any non-home non-legendary planet to gain legendary status. Notably, there is no associated ability card.
Volume III: Vigil[]
Volume III introduced a new faction, The Council Keleres, whose faction technology I.I.H.Q Modernization allows them access to a unique legendary planet called Custodia Vigilia.
Note that this does not come with an associated system tile.
| Planet | Trait | Resources | Influence | Ability | Flavor Text |
|---|---|---|---|---|---|
| Custodia Vigilia | - | 2 | 3 | Custodia Vigilia
While you control Mecatol Rex, it gains SPACE CANNON 5 and PRODUCTION 3. Gain 2 command tokens when another player scores Victory Points using imperial. |
Custodia Vigilia. The fully realized seat of the Keleres. A veritable fortress in the heart of Mecatol City. Ten thousand people come and go daily, and the Keleres see them all. |
Anomalies[]
Some system tiles contain anomalies. These systems restrict movement and have special rules governing them. They are identified by a red border located on the tile's corners.
Some anomalies (introduced in the Prophecy of Kings Expansion) contain planets; those systems are still anomalies.
Abilities can cause a system tile to become an anomaly (e.g. Placing a Dimensional Tear); that system tile is an anomaly in addition to its other properties.
Abilities can cause a system to be two different anomalies; that system has the properties of both anomalies.
Asteroid Field[]
- A ship cannot move through or into an asteroid field.
Nebula[]
- A ship cannot move through, but may move into a nebula.
- A ship cannot move into a nebula unless it is the active system (i.e. it cannot be the destination of a Retreat, Skilled Retreat or similar effects). - Note: As per Dane Beltrami on 17/06/21 this will be removed on the next LRR update
- If a space combat occurs in a nebula, the defender applies +1 to each combat roll of their ships during that combat.
- A ship that begins the “Movement” step of a tactical action in a nebula treats its move value as “1” for the duration of that step.
Supernova[]
- A ship cannot move through or into a supernova.
Gravity Rift[]
- A ship that will move out of or through a gravity rift at any time during its movement, applies +1 to its move value (This can allow a ship to reach the active system from farther away than it normally could).
- For each ship that would move out of or through a gravity rift, 1 die is rolled immediately before it exits the gravity rift system; on a result of 1–3, that ship is removed from the board.
- Dice are not rolled for units that are being transported by ships that have capacity.
- Units that are being transported are removed from the board if the ship transporting them is removed from the board.
- Units that are removed are returned to the player’s reinforcements.
- A gravity rift can affect the same ship multiple times during a single movement.
- A system that contains multiple gravity rifts is treated as a single gravity rift.
Prophecy of Kings Expansion[]
The Prophecy of Kings Expansion introduced the following Anomalies:
- The Dark (Empyrean Home System): Is a nebula
- Cormund System: Contains the Hazardous planet Cormund in addition to a Gravity Rift
- Everra System: Contains the Cultural planet Everra in addition to a Nebula
- Asteroid/Alpha System: A System Containing an Asteroid Field as well as an Alpha Wormhole
- Supernova: An additional Supernova tile
- Muaat Supernova: A Supernova tile for the Muaat Hero ability
Wormholes[]
Some systems contain wormholes. Wormholes are not considered anomalies. There are two basic types of wormholes: alpha and beta. Systems that contain identical wormholes are adjacent (e.g. alpha-alpha).
PDS units that have been upgraded by the “PDS II—Deep Space Cannon” unit upgrade technology can use their “Space Cannon” abilities through wormholes. Players can be neighbors and perform transactions through wormholes.
Advanced Wormholes[]
Delta Wormhole[]
- This wormhole is present on the Creuss Gate system tile and the Ghosts of Creuss home system tile
- It follows all normal wormhole rules
Gamma Wormhole[]
Gamma Wormhole token
- The Prophecy of Kings expansion introduced an additional advanced wormhole - the Gamma Wormhole.
- The Wormhole Nexus initially contains only a gamma wormhole but when flipped contains an Alpha, Beta and Gamma wormhole.
- Gamma wormholes may be acquired by resolving certain cards in the exploration and frontier decks
as well as one card in the Agenda deck.
Ion Storms[]
Ion storm Token
The Prophecy of Kings expansion also introduced the Ion Storm wormhole, a token which comes into play in a Frontier system when the "Ion Storm" card is revealed. The token has the "alpha" symbol on one side and the "beta" symbol on the other.
At the end of a "Move Ships" or "Retreat" sub-step of a tactical action during which 1 or more of a player's ships use the ion storm wormhole, flip the ion storm token to its opposing side.
The Wormhole Nexus[]
The Wormhole Nexus is a Special System that introduced in the Prophecy of Kings expansion that is placed outside the main board setup (similar to the Creuss home system) and may only be accessed via a Gamma (γ) Wormhole. (Note: It is still counted as being on the Game Board for the Purpose of Cards and Abilities).
At Game Setup, it is placed on its INACTIVE SIDE and contains the Legendary Planet Mallice (see above), along with a Gamma Wormhole. The first time a player moves or places a unit into the wormhole nexus or gains control of its planet (Mallice), the player flips it to its ACTIVE SIDE, which contains an Alpha, Beta and Gamma Wormhole (Thus it is now adjacent to any system with an alpha, beta or gamma wormhole).
The wormhole nexus is on the edge of the game board for the purpose of scoring objectives.
Empty Space[]
Some systems contain no planets, wormholes or anomalies. Five such systems are present in the base game. These systems may be moved into and out of as normal, and consist only of "space area."
Hyperlane Tiles[]
Introduced in the Prophecy of Kings Expansion, Hyperlane tiles are tiles with bright lines between edges, in a variety of variations
When playing with 5 or 7 players, the galaxy is recommended to be set up with hyperlane tiles
System tiles connected by a hyperlane are adjacent for all purposes
Hyperlane tiles are not systems. They cannot have units on them and they cannot be targets for effects or abilities.
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| Fourth Edition |  | |
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| Second Edition | (No additional pages) | |
| First Edition | (No additional pages) | |