TI4 Rules DeskTwilight Imperium 4
Common mistakes

Rules everyone gets wrong

22 frequent misreadings. The myth and the short correction are our summaries; the quoted text below each is the official rule, word for word.

1. Counting fighters against the fleet pool

Myth: Every ship in a system, fighters included, counts toward your fleet pool limit.
Actually: Only non-fighter ships count against the fleet pool. Fighters count against the capacity of your ships instead.
The number of command tokens in a player’s fleet pool indicates the maximum number of non-fighter ships that a player can have in a system.
a. Units that are on planets or that count against a player’s capacity do not count against that player’s fleet pool.
b. Units that are being transported through systems do not count against a player’s fleet pool in those systems.LRR 37.1 · Fleet Pool
A player can have a number of ships in a system equal to or less than the number of command tokens in that player’s fleet pool.
a. Fighters do not count toward the fleet pool limit, and instead count against a player’s capacity.LRR 76.2 · Ships

2. Firing anti-fighter barrage every round

Myth: Destroyers roll anti-fighter barrage at the start of each combat round.
Actually: Anti-fighter barrage is only resolved during the first round of a space combat.
STEP 1—ANTI-FIGHTER BARRAGE: If this is the first round of a space combat, the players may simultaneously use the “Anti-Fighter Barrage” ability of any of their units in the active system.
a. If one or both players no longer have ships in the active system after resolving this step, the space combat ends immediately.
b. Players cannot resolve “Anti-Fighter Barrage” abilities during any rounds of space combat other than the first round.
c. This step still occurs if no fighters are present.LRR 78.3 · Space Combat

3. Thinking sustain damage only works in combat

Myth: Sustain damage can only cancel hits from combat rolls.
Actually: A unit can sustain damage against any hit produced against it, including space cannon and anti-fighter barrage, but not against effects that destroy a unit directly.
A unit can use its “Sustain Damage” ability any time a hit is produced against it. This includes hits produced during combat and from unit abilities such as the “Space Cannon” ability.
a. A unit can only use the “Sustain Damage” ability if it is eligible to be hit. For example, a player cannot use a dreadnought’s “Sustain Damage” ability to cancel a hit from “Anti-Fighter Barrage.”LRR 87.4 · Sustain Damage (Unit Ability)
The “Sustain Damage” ability cannot be used to cancel an effect that directly destroys a unit.LRR 87.5 · Sustain Damage (Unit Ability)

4. Spending trade goods to cast votes

Myth: Trade goods can be spent as influence for votes in the agenda phase.
Actually: Trade goods can be spent as influence in general, but never to cast votes.
Trade goods cannot be spent to cast votes.LRR 8.13 · Agenda Phase
A player can spend a trade good as if it were one influence.
a. Players cannot spend trade goods to cast votes during the agenda phase.LRR 47.3 · Influence

5. Moving ships out of a system with your own command token

Myth: Ships can leave any system as long as they have enough move.
Actually: A ship cannot move if it started its movement in a system that contains one of your command tokens — though it can move through such systems.
STEP 1—MOVE SHIPS: A player can move any number of their eligible ships into the active system, obeying the following rules:
a. The ship must end its movement in the active system.
b. The ship cannot move through a system that contains ships that are controlled by another player.
c. The ship cannot move if it started its movement in another system that contains one of its faction’s command tokens.
d. The ship can move through systems that contain its own faction’s command tokens.
e. The ship can move out of the active system and back into it if its move value is high enough.
f. The ship must move along a path of adjacent systems, and the number of systems the ship enters cannot exceed its move value.LRR 58.4 · Movement

6. Picking up units from a system you already activated

Myth: A carrier passing through can pick up fighters and ground forces from any system.
Actually: Fighters and ground forces cannot be picked up from a system that contains one of your command tokens, other than the active system.
Fighters and ground forces cannot be picked up from a system that contains one of their faction’s command tokens other than the active system.LRR 95.3 · Transport

7. Spending commodities like trade goods

Myth: Commodities on your faction sheet can be spent like trade goods.
Actually: Commodities cannot be spent; they become trade goods only when you give them to another player in a transaction.
A player cannot spend commodities unless otherwise specified; a player can only trade them during a transaction.LRR 21.7 · Commodities
Players can trade commodities following the rules for transactions. When a player receives a commodity from another player, the player who received that token converts it into a trade good by placing it in the trade good area of their command sheet with the trade good side faceup.
a. That token is no longer a commodity token; it is a trade good token.
b. A player can trade commodity tokens before resolving a game effect that allows them to replenish commodities.
c. If a game effect instructs a player to convert a number of their own commodities to trade goods, those trade goods are not treated as being gained for the purpose of triggering other abilities.LRR 21.5 · Commodities

8. Producing a pair of fighters for one production

Myth: Two fighters (one cost) count as one unit toward a space dock's PRODUCTION limit.
Actually: Each individual fighter or infantry counts toward the producing unit's PRODUCTION value.
A unit’s “Production” ability, which is presented on a faction sheet or unit upgrade technology card, is always followed by a value. This value is the maximum number of units that this unit can produce.
a. If the active player has multiple units in the active system that have the “Production” ability, that player can produce a number of units up to the combined total of their units’ production values in that system.
b. When producing fighters or infantry, each individual unit counts toward the producing unit’s production limit.
c. A player can choose to produce one fighter or infantry instead of two, but must still pay the entire cost.
d. “Production” value from Arborec space docks cannot be used to produce infantry, even if the Arborec player controls other units that have “Production” in the same system.LRR 68.1 · Production (Unit Ability)
If the cost is accompanied by two icons—typically for fighters and infantry—a player produces two of that unit for that cost.
a. Each of the two units counts toward the total number of units a player can produce.
b. A player can choose to produce only one unit; however, they must still pay the entire cost.LRR 67.2 · Producing Units

9. Producing ships next to enemy ships

Myth: A space dock can always produce ships in its system.
Actually: You cannot produce ships in a system that contains other players' ships, and a blockaded unit cannot produce ships.
A player cannot produce ships in a system that contains other players’ ships.
a. Ground forces can still be produced.LRR 67.6 · Producing Units
A player cannot use a blockaded unit to produce ships; that player can still use a blockaded unit to produce ground forces.LRR 14.1 · Blockaded

10. Scoring public objectives while your home is occupied

Myth: You can score any public objective you meet the requirement for.
Actually: You cannot score public objectives unless you control each planet in your home system.
A player cannot score public objectives if that player does not control each planet in their home system.LRR 61.16 · Objective Cards

11. Scoring several objectives in one status phase

Myth: In the status phase you can score every objective you qualify for.
Actually: During each status phase, a player can score at most one public objective and one secret objective.
A player can score a maximum of one public objective and one secret objective during each status phase.LRR 61.6 · Objective Cards
STEP 1—SCORE OBJECTIVES: Following initiative order, each player may score up to one public objective and one secret objective that can be fulfilled during the status phase. To score an objective, a player must fulfill the requirements on the card; if that player does, they gain a number of victory points indicated on the card.LRR 81.1 · Status Phase

12. Forgetting the nebula rules

Myth: A nebula only blocks movement.
Actually: Ships can only move into a nebula if it is the active system, ships starting in a nebula have move 1, and the defender gets +1 to combat rolls in a nebula.
A ship can only move into a nebula if it is the active system.
a. A ship cannot move through a nebula. That is, a ship cannot move into and out of a nebula during the same movement.LRR 59.1 · Nebula
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.
a. Other abilities and effects can increase this number.LRR 59.2 · Nebula
If a space combat occurs in a nebula, the defender applies +1 to each combat roll of their ships during that combat.LRR 59.3 · Nebula

13. Getting the gravity rift bonus repeatedly

Myth: A ship can chain several gravity rifts (or the same one twice) for multiple bonuses.
Actually: Under Thunder's Edge's clarification, a gravity rift can only contribute its movement bonus to ships that pass through it once per ship; each exit still risks destruction on a 1–3.
A ship that will move out of or through a gravity rift at any time during its movement, applies +1 to its move value.
a. This can allow a ship to reach the active system from farther away than it normally could.LRR 41.1 · Gravity Rift
For each ship that would move out of or through a gravity rift, one die is rolled immediately before it exits the gravity rift system; on a result of 1–3, that ship is removed from the board.
a. Dice are not rolled for units that are being transported by ships that have capacity.
b. Units that are being transported are removed from the board if the ship transporting them is removed from the board.
c. Units that are removed are returned to the player’s reinforcements.LRR 41.2 · Gravity Rift
• A gravity rift can only contribute its movement bonus to ships that pass through it once per ship. This is a change from previous rulings.TE clarification: Gravity Rift (Anomaly)

14. Passing before using your strategy card

Myth: You may pass at any time during the action phase.
Actually: A player cannot pass until they have performed the strategic action of their strategy card (both cards in three- and four-player games).
A player cannot pass until they have performed the strategic action of their strategy card.
a. During a three-player or four-player game, a player cannot pass until they have exhausted both of their strategy cards.LRR 3.4 · Action Phase

15. Holding more than seven action cards

Myth: There's no hand limit on action cards.
Actually: Your hand can contain at most seven action cards; discard down if you ever exceed it.
Each player’s hand can have a maximum of seven action cards. If a player ever has more than seven action cards, that player must choose seven cards to keep and discard the rest.
a. A game effect can increase or decrease the number of cards a player’s hand can have.LRR 2.4 · Action Cards

16. Letting fighters overflow during combat

Myth: Excess fighters are removed as soon as carriers are destroyed mid-combat.
Actually: Fighters and ground forces do not count against capacity during combat; check capacity at the end of combat.
If a player has more fighters and ground forces in the space area of a system than the total capacity of that player’s ships in that system, that player must remove the excess units.
a. A player can choose which of their excess units to remove.
b. Ground forces on planets do not count against capacity.
c. A player’s fighters and ground forces do not count against capacity during combat. At the end of combat, any excess units are removed and returned to that player’s reinforcements.LRR 16.3 · Capacity (Attribute)

17. Paying a token for Leadership's secondary

Myth: Every strategy card secondary costs a command token from the strategy pool.
Actually: The Leadership secondary is the exception — it does not cost a command token.
After a player performs a strategic action during the action phase, each other player can resolve the secondary ability of that strategy card by spending a command token from their strategy pool.
a. A player does not spend a command token to resolve the secondary ability of the “Leadership” strategy card.LRR 20.5 · Command Tokens
After the active player resolves the primary ability of the “Leadership” strategy card, each other player, beginning with the player to the left of the active player and proceeding clockwise, may spend any amount of influence to gain one command token for every three influence they spend.LRR 52.3 · Leadership (Strategy Card)

18. Retreating anywhere

Myth: You can retreat into any adjacent system, and both players may announce a retreat.
Actually: If the defender announces a retreat, the attacker cannot; you must retreat to an adjacent system with your units or a planet you control and no other players' ships.
STEP 2—ANNOUNCE RETREATS: Each player may announce a retreat, beginning with the defender.
a. A retreat will not occur immediately; the units retreat during the “Retreat” step.
b. If the defender announces a retreat, the attacker cannot announce a retreat during that combat round.
c. A player cannot announce a retreat if there is not at least one eligible system to retreat to.LRR 78.4 · Space Combat
STEP 5—RETREAT: If a player announced a retreat during step 2, and there is still an eligible system for their units to retreat to, they must retreat.
a. If a player announced a retreat during the “Announce Retreats” step, but their opponent has no ships remaining in the system, the combat immediately ends and the retreat does not occur.
b. To retreat, a player takes all of their ships with a move value in the combat and moves them to a single system that is adjacent to the active system. That player’s fighters and ground forces in the space area of the active system that are unable to move or be transported are removed.
c. The system that a player’s units retreat to must contain one or more of that player’s units, a planet they control, or both. Additionally, the system cannot contain ships controlled by another player.
d. If any of a player’s units successfully retreat and are moved into an adjacent system, that player must place a command token from their reinforcements in the system to which their units retreated. If that system already contains one of their command tokens, that player does not place an additional token there. If the player has no command tokens in their reinforcements, that player must use one from their command sheet instead.LRR 78.7 · Space Combat

19. Treating 'removed' as 'destroyed'

Myth: A unit removed from the board triggers 'when destroyed' effects.
Actually: A unit removed by a game effect is not destroyed, so destruction triggers don't apply.
If a player’s unit is removed from the board by a game effect, it is not treated as being destroyed; effects that trigger when a unit is destroyed are not triggered.LRR 31.2 · Destroyed

20. Breaking agenda ties by revote

Myth: Ties are re-voted, or no outcome is resolved.
Actually: The speaker decides between tied outcomes (or chooses if nothing received votes); this is not a vote.
If there is a tie for the outcome that received the most votes, or if no outcome receives any votes, the speaker decides which of the tied outcomes to resolve.
a. The speaker’s decision is not a vote.LRR 8.19 · Agenda Phase

21. Exploring planets taken from another player

Myth: Every time you gain control of a planet you explore it.
Actually: You only explore a planet when you gain control of it and it is not already controlled by another player.
When a player takes control of a planet that is not already controlled by another player, they explore that planet.LRR 35.1 · Exploration
When a player gains control of a planet, they take the planet card that corresponds to that planet and place it in their play area; that card is exhausted.
a. If a player is the first player to control a planet, they take the planet card from the planet card deck.
b. If another player controls the planet, they take that planet’s card from the other player’s play area.
c. When a player gains control of a planet that is not already controlled by another player, they explore that planet.LRR 25.1 · Control

22. Rerolling the same die again and again

Myth: An ability that rerolls can be used repeatedly on one die.
Actually: The same ability cannot reroll the same die multiple times — though different abilities can each reroll it.
The same ability cannot be used to reroll the same die multiple times, but multiple abilities can be used to reroll a single die.LRR 74.2 · Rerolls