Twilight Imperium: Fourth Edition – Thunder's Edge Rulebook

Table of Contents

Table of Contents

• Components
• Expansion Integration
• Setup
  • Setup Variations
• Rules
  • Thunder's Edge Expedition
  • Breakthroughs and Synergy
  • The Fracture
  • Relics
  • Legendary Planets
  • Neutral Units
  • Purge
  • Space Stations
  • Entropic Scar Anomaly
  • Dual Planet Traits
  • Dual Specialties
  • Coexist
• Alliance Game Variant
  • Alliance Setup
  • Alliance Combat and Unit Abilities
  • Alliance Abilities and Effects
  • Alliance Transactions
  • Alliance Movement and Control
  • Alliance Elimination
  • Alliance Winning the Game
• Map Appendix
• Clarifications
• Thunder's Edge Expedition Quick Reference

Components

Thunder's Edge contains the following components, as listed on the printed components page:

• 7 faction sheets
• 2 revised strategy cards (Construction and Warfare)
• 63 plastic neutral units
• 1 Thunder's Edge token
• 33 system and hyperlane tiles
• 3 Fracture system tiles
• 20 galactic event cards
• 30 faction reference cards
• 43 planet cards
• 31 alliance reference cards
• 20 action cards
• 30 breakthrough cards
• 10 legendary planet ability cards
• 10 relic cards
• 6 promissory note cards
• 10 faction technology cards
• 16 faction mechanic cards (5 Firmament plot cards, 5 Deepwrought ocean cards, and 6 Helios cards)
• 74 codex cards
• 24 Prophecy of Kings cards (19 leaders and 5 mechs)
• 1 reference card (neutral unit reference)
• 1 Avernus planet token
• 1 Nano-Forge attachment token
• 2 Empyrean void tether tokens
• 7 Nekro Z assimilator tokens
• 7 ingress tokens
• 1 diplomacy token
• 7 Crimson breach tokens (double-sided)

Expansion Integration

Use the diagram on the printed integration page as a reference and perform the following steps to integrate Thunder's Edge with the base game and Prophecy of Kings.

First, find the cards packaged with the "Codex Cards" cover card, also identifiable by the Twilight Codex expansion icon.

If you do not have a previous version of the Twilight Codex, combine the following components with like components from the base game and expansions:

• 20 action cards
• 1 Keleres promissory note
• 3 relics
• 2 Keleres faction technologies
• 6 exploration cards
• 1 Keleres faction sheet
• 1 Keleres mech
• 5 Keleres leaders
• 1 "Custodia Vigilia" planet card
• 1 "Custodia Vigilia" legendary planet ability

Then, for each remaining codex card, find and replace each corresponding component from the base game or Prophecy of Kings. In total, you will replace:

• 3 faction technologies
• 5 promissory notes
• 8 "Magen Defense Grid" cards
• 1 mech
• 8 "X-89 Bacterial Weapon" cards
• 6 leaders
• 3 secret objectives

If you do have a previous version of the Twilight Codex, simply replace all of its components with the updated versions included in Thunder's Edge.

Additionally, Thunder's Edge comes with its own complete sets of alliance and faction reference cards. The print-and-play versions introduced by the Twilight Codex are not used.

Replace the "Construction" and "Warfare" strategy cards with the revised versions included with Thunder's Edge.

Replace the "Mecatol Rex" system tile from the base game with the "Mecatol Rex" system tile that has a legendary planet icon.

If you are playing with the Prophecy of Kings expansion, replace the Jol-Nar's "Ta Zern" leader with their "Agnlan Oln" leader.

If you are not playing with the Prophecy of Kings expansion, remove all leaders, mechs, and exploration cards, as well as the "Cultural Exchange Program" galactic event.

Finally, combine any remaining new cards with their respective decks, and shuffle the red-backed and blue-backed system tiles into their respective piles.

Components used in the Twilight's Fall game mode are not used when playing a normal game. See the Twilight's Fall component list in the Twilight's Fall rulebook for a list of these components.

Setup

To set up a game of Twilight Imperium with the Thunder's Edge expansion, follow the Complete Setup rules found in the rules reference with the following additions:

• Step 1 – Determine speaker: After the speaker has been determined, the players may, as a group, optionally choose or draw at random a galactic event card to put into play. Some galactic events may further modify setup. Advanced player groups are free to play with more than one galactic event, should they desire.

At the end of setup, all players other than the Embers of Muaat player gain the War Sun unit upgrade technology. The Embers of Muaat player purges their faction-specific promissory note and places 1 additional War Sun in their home system.

• Step 3 – Gather faction components: In addition to their faction components from the base game and other expansions, each player takes their faction's breakthrough card. The factions listed below take additional components:

  • The Embers of Muaat: 1 Avernus token.
  • The Nekro Virus: 7 Assimilator Z tokens, 3 Helios tokens, and 3 Helios cards.
  • The Empyrean: 2 Void Tether tokens.
  • The Crimson Rebellion: 1 Sever and 7 Breach tokens.
  • The Deepwrought Scholarate: 5 Ocean cards.
  • The Firmament: 5 Plot cards, all Obsidian components.
  • Last Bastion: 8 Galvanize tokens, 3 Helios tokens, and 3 Helios cards.

  Last Bastion's faction ability, The Icon, reads: "When you produce ships, you may exhaust this card to place those ships in a system that contains 1 of your command tokens, at least 1 of your ground forces, and no other player's ships."

• Step 4 – Choose color: Players that wish to use the color-based command tokens and control tokens from the Twilight's Fall game mode may choose to do so rather than the standard faction-specific command tokens and control tokens. This may help with board clarity for novice players.

• Step 6 – Create game board: After the galaxy has been created, set aside the three tiles that make up The Fracture; these tiles may come into play during the game.

• Step 7 – Place game board tokens: Place the Thunder's Edge token, expedition side faceup, in the common play area.

Setup Variations

When playing at certain player counts or with the "Minor Factions" galactic event, the "Create Game Board" step (step 6) of setup is modified as described below.

Four-player setup. This setup is used only when also playing with Prophecy of Kings. During the "Deal System Tiles" substep, each player is dealt three blue tiles and two red tiles. Before the "Place System Tiles" substep, the players place the hyperlane tiles exactly as shown in the "Game Board Setup" diagram.

Five-player setup. During the "Deal System Tiles" substep, each player is dealt three blue tiles and two red tiles. Before the "Place System Tiles" substep, the players place the hyperlane tiles exactly as shown in the "Game Board Setup" diagram. Extra trade in five-player games based on starting position are not given to players during setup when playing with hyperlanes.

Minor Factions setup. If playing with the "Minor Factions" galactic event, the "Game Board Setup" diagram provides an example setup that depicts valid placement for the Minor Faction systems.

Hyperlane setup. For the game board setups described in this section, hyperlane tiles are always set up in the formation shown in the Hyperlane Setup diagram, using hyperlane tiles 119A, 120A, 121A, 122A, 123A, and 124A. The rules for hyperlanes are described under Hyperlanes below.

Rules

This section describes the components and mechanics introduced in this expansion.

Thunder's Edge Expedition

Players may venture to Thunder's Edge to unlock powerful new abilities and potentially earn the right to claim the planet of Thunder's Edge for their faction. Thunder's Edge begins the game in play, off the board, with its expedition side—the side divided into six "slices"—faceup.

At the end of a player's turn, they may commit to the expedition. To do so, they choose an unclaimed slice of the expedition and pay the indicated cost, placing one of their control tokens in that slice to indicate that it has been claimed.

The expedition costs are as follows:

• Spend 5 resources.
• Discard 1 unscored secret objective.
• Discard 2 action cards.
• Exhaust 1 technology specialty planet.
• Spend 5 influence.
• Spend 3 trade goods.

Once claimed, that slice cannot be claimed by another player, which means other players must choose a different cost to pay in order to contribute to the expedition. The first time a player claims one of the expedition slices, they gain their faction's breakthrough. A player can claim multiple expedition slices in a game, but must choose a different unclaimed slice each time they do so.

When all slices are claimed, the expedition is complete; the player who claimed the final slice flips Thunder's Edge to its planet side and places it in a system of their choice that does not contain a planet, a supernova, or a printed wormhole. Then, the player with the most control tokens on the expedition places that many infantry on Thunder's Edge. In the case of a tie, the player who claimed the final slice chooses which tied player places infantry on Thunder's Edge. Thunder's Edge cannot be placed in The Fracture.

Breakthroughs and Synergy

A breakthrough is a new type of faction-specific component, most commonly gained by interacting with Thunder's Edge. A breakthrough will give each faction a unique new ability and grants synergy between two technology colors.

Synergy links two colors of technology. A technology or technology specialty of a color that a player has synergy with can count as the other color instead, for the purposes of researching technology and for scoring technology-related objectives. Even so, a technology can only count as one or the other at any given time, not both.

Each time a breakthrough is gained, there is a possibility that The Fracture will come into play. When a player gains their breakthrough, regardless of the source, if The Fracture is not already in play, they roll one die. If their die roll is equal to 1 or 10, they put The Fracture into play.

The Fracture

The Fracture is an enigmatic area of space that is not connected to the rest of the galaxy. When The Fracture comes into play, the player that brought it into play places it along any edge of the game board, based on player count, as shown in "The Fracture" diagram. They then place neutral units as indicated on the back of The Fracture's tiles.

If The Fracture was brought into play by a breakthrough roll, the rolling player places ingress tokens on the game board. For each synergy color on their breakthrough, that player must choose three systems that contain matching technology specialties, if able, and place ingress tokens in those systems. A system cannot have more than one ingress token, and no more than six ingress tokens can be placed in this way.

If The Fracture was brought into play by another ability, or by a breakthrough that does not have synergy (as is the case with the Nekro Virus faction), the player chooses four planets and places an ingress token in those planets' systems. Each planet must be in a different system and must have a different technology specialty. If there are not four different technology specialties in play, the remaining ingress tokens are not placed.

Finally, the players place an ingress token in the Thunder's Edge system, if it is in play, or in the Mecatol Rex system, if the expedition has not been completed.

Regardless of where The Fracture is placed, its systems are not adjacent to the systems it is touching, and each of its systems is considered to be on the edge of the game board. Access to The Fracture is possible through ingress tokens. A system that contains an ingress is adjacent to each system in The Fracture that contains an egress. However, ingress systems are not adjacent to other ingress systems, and egress systems are not adjacent to other egress systems.

Planets inside The Fracture are highly rewarding. Each planet in the Fracture has a relic icon. One planet, Styx, has both a relic icon and is a legendary planet.

Relics

When a player gains a planet card from the planet deck that has a relic icon, or when a game effect tells them to draw a relic, they draw the top card of the relic deck and place it faceup in their play area. Relics provide players with powerful abilities that can change the course of the game.

Legendary Planets

Many of the planets in this expansion are legendary planets, which are indicated by the legendary icon.

When a player takes control of a legendary planet, they also place its legendary planet ability card in their play area. Each legendary planet ability card grants its owner a unique and powerful ability. If a player gains control of an exhausted legendary planet ability card, it remains exhausted.

The printed example is Styx, with its planet card and its legendary planet ability card, "A Song Like Marrow." That card reads: "When you gain this card, gain 1 victory point. When you lose this card, lose 1 victory point."

Neutral Units

Neutral units are non-player forces that engage a player in combat if the player moves units to the planet or space area that those neutral units occupy. Neutral units' combat stats are indicated on the neutral unit reference card, and their rolls are made by any player other than the active player. During combat, hits are assigned to neutral units in the order presented on the neutral unit reference, prioritizing units lower on the reference card first (for example, hits will always be assigned to neutral destroyers before they are assigned to neutral cruisers).

Neutral units always use unit abilities when they can (sustain damage, space cannon, etc.) but are otherwise unable to use any other abilities. Neutral units do not take turns or perform any other game function unless explicitly stated by rule or ability text. Neutral units count as other player's units for the purpose of resolving players' abilities and other game effects. There is, however, no "neutral player," and neutral units are incapable of making decisions; in the unlikely event that a decision needs to be made for a neutral unit, the speaker makes that decision instead.

The neutral unit reference card lists the following neutral units (combat, move, capacity as printed):

• Flagship: sustain damage; 7 combat, 1 move, 3 capacity.
• War Sun: sustain damage; bombardment 3 (x3); 3 combat, 2 move, 6 capacity.
• Dreadnought: sustain damage; bombardment 5; 5 combat, 2 move, 1 capacity.
• Carrier: 9 combat, 2 move, 6 capacity.
• Cruiser: 6 combat, 3 move, 1 capacity.
• Destroyer: anti-fighter barrage 6 (x3); 8 combat, 2 move.
• Fighter: 8 combat, 2 move.
• Mech: sustain damage; 6 combat.
• Infantry: 8 combat.
• PDS: planetary shield; space cannon 6.
• Space dock.

Purge

If an ability instructs a player to purge a component, that component is removed from the game and returned to the box.

Space Stations

Some systems contain space stations. A player gains control of a space station from the deck or from another player when they are the only player that has ships in its system. They do not lose control of the station if those ships move out of its system. Each space station has a corresponding planet card, which is gained exhausted and is spent, readied as if it were a planet. However, structures and ground forces cannot be placed on or committed to space stations, and they do not count as planets for the purpose voting, objectives, or controlling a home system.

A player's commodity value is increased by 1 for each space station they control; corresponding commerce tokens are placed in their commodity pool as a reminder. A player that controls a space station can resolve transactions with other players that control a space station, even if they are not neighbors. Finally, players can exhaust a space station at any time to convert their commodities to trade goods.

Entropic Scar Anomaly

An entropic scar is a new kind of anomaly. All unit abilities (sustain damage, production, planetary shield, space cannon, bombardment, deploy, and anti-fighter barrage) cannot be used by or against units inside of an entropic scar. Text abilities are unaffected. Additionally, wormholes that would be placed inside of an entropic scar are discarded instead.

At the start of the status phase, a player that has ships in an entropic scar can spend a token from their strategy pool to gain one of their faction-specific technologies.

Dual Planet Traits

Planets that have dual planet traits count as having both traits. When exploring one of these planets with the Prophecy of Kings expansion, the exploring player can choose to draw a card matching either of the planet's traits (but not both).

The printed examples are a cultural/hazardous planet, a hazardous/industrial planet, and an industrial/cultural planet.

Dual Specialties

Some planets have two technology specialties. These planets can be exhausted when researching technology to satisfy either or both prerequisites simultaneously.

Coexist

Some game effects allow a player's units to coexist with other units on a planet. When a unit or units coexist with another player's units, they do not trigger combat. The player whose units triggered coexistence does not gain or retain control of the planet; if they already controlled it, the player they are now coexisting with gains control of it instead, exhausted. Coexisting structures are always blockaded. If the coexisting player places, produces, or moves additional units onto that planet, those units also coexist. If a player's coexisting units become the only units on a planet, that player gains control of the planet.

Coexisting units can be bombarded. When a player makes a bombardment roll against a planet, they choose which of their units with bombardment are bombarding which other player's units, rolling against each player separately.

Coexisting units can have combat initiated against them by units being committed to the planet that contains them, including units that they were already coexisting with. The activating player may choose not to engage the coexisting units, however, and leave the coexisting units in a state of coexistence. If a player does wish to engage coexisting units, they may optionally engage a coexisting player's units after winning a combat against the planet's owner, initiating separate combats against any coexisting player as desired.

Likewise, a coexisting player may choose to end their coexistence by activating the coexisting unit's system and committing the coexisting units against the planet they are coexisting on. If they win the ground combat, they cease coexisting and gain control of the planet as normal.

When scoring objectives, a coexisting player counts as controlling the planet they are coexisting on; they do not count as controlling the planet for any other game ability or effect.

Hyperlanes

When playing with five players, or when playing with four players and the Prophecy of Kings expansion, the galaxy is set up with hyperlane tiles (see "Game Board Setup" in the Setup Variations section). Each contiguous line created by one or more hyperlane tiles is a hyperlane. System tiles connected by a hyperlane are considered adjacent for all purposes.

Hyperlane tiles improve balance in the starting positions for each player, so players in five-player games do not receive extra trade goods for having a particular starting position.

Hyperlane tiles are not systems. They cannot have units on them and they cannot be targets for effects or abilities.

Faction Reference Cards

These cards contain a short summary of a faction's capabilities, including those granted by cards in Prophecy of Kings. These cards are also used during setup of the Twilight's Fall game mode and with Galactic Events to determine random factions.

Alliance Reference Cards

These cards are a reference for when playing with the Prophecy of Kings "Alliance" promissory note. These cards are also used in the Alliance game variant, in some Galactic Events, and with the Yin Brotherhood's breakthrough card.

When gained for any reason other than a reference to an "Alliance" promissory note, the gaining player places the card in their play area. They can use its ability.

Galactic Events

Galactic events are optionally selected during game setup and can change the parameters of play. Each event is different and contains the rules needed to play.

Diplomacy Token

This token is a player aid included to facilitate ease of play when resolving simple uses of the "Diplomacy" strategy card's primary ability. It represents a command token from each player. It cannot be used to bring a player above the component limit for command tokens and should not be used when interacting with abilities that remove command tokens.

Alliance Game Variant

In this game variant, players form teams of two against up to three other alliances. This can be played with four, six, or eight players. To accommodate team play, the rules are modified as follows:

Alliance Setup

• Step 2 – Choose factions: Each player must also be assigned an ally. Determine which pairs of players will be allies. Each player takes the Alliance reference card that corresponds to their ally and places it in their play area.

  Note: The ally of the Mahact Gene-Sorcerers faction also places a command token from their reinforcements into the Mahact's fleet pool.

• Step 4 – Choose color: If playing with the Prophecy of Kings expansion, each player purges their "Alliance" promissory note and flips their commander to its unlocked side; all commanders are unlocked at the start of the game.

Alliance Combat and Unit Abilities

• During a combat roll or a roll for a unit ability where a player and their ally each have units present, both can participate in the same roll; their rolls are combined and hits are assigned as normal. When an opposing force produces hits against allied players, the allies will decide together which units the hits will be assigned against; if they cannot come to a consensus, the active player assigns the hits.
• Effects that produce hits that are assigned by an opponent against an allied pair can be assigned to either ally's units in any combination.

Alliance Abilities and Effects

• Your ally's units count as neither your units nor as other players' units for the purpose of resolving game effects and abilities.
• Abilities that trigger when a player activates a system that contains another player's units, planets, or command tokens do not trigger when those players are allies.
• Your unit abilities (space cannon, planetary shield, etc.) do not affect your ally.
• Agent abilities can be used on your ally.
• Your ally's planets count as your planets for the purpose of resolving abilities, but you cannot exhaust them and they do not count for scoring objectives or scoring the "Imperial" victory point.

Alliance Transactions

When performing transactions with your ally, players follow a modified set of rules:

• When you exchange commodities with your ally, they do not convert into trade goods.
• While you may receive promissory notes from your ally as part of a transaction (to later give to another player, for example), you cannot resolve those promissory notes.

Alliance Movement and Control

• Your ships may move through and into systems that contain your ally's ships; this does not trigger a space combat.
• Your ground forces may land on planets controlled by your ally; this does not trigger a ground combat or cause you to gain control of that planet.
• When a game effect allows a player to redistribute command tokens, they may also exchange planet cards with their ally, provided that the receiving player has at least 1 ground force or structure on that planet. This exchange does not change the ready or exhausted state of a planet card and does not trigger abilities that occur when you gain control of a planet.
• When your ally activates a system, you may simultaneously perform a tactical action in that system with your ally; if you do, you must spend and place a token from your tactic pool as normal.
• You may, if your ally allows it, transport, support, and commit their fighters and ground forces using your units that have capacity.

Alliance Elimination

• A player cannot be eliminated as long as their ally controls a planet.

Alliance Winning the Game

• The game is played using the "14" side of the victory point track. One player must have 14 victory points and their ally must have at least 10 victory points in order for that alliance to win the game.

Map Appendix

The Twilight Imperium community is filled with many talented map-makers. The printed rulebook offers the following premade maps; their tile layouts are pictures and are not transcribed.

• "Thunder Dreaming": ideal for six novice players and a balanced game experience that showcases many new Thunder's Edge tiles but does not require the Prophecy of Kings expansion.
• Minor Factions map (title printed in a symbol font): used for an amped-up game of the "Minor Factions" galactic event. The Prophecy of Kings expansion is required. Each player chooses from among the factions shown on the page. Randomly set up each unchosen faction's home system in the red spaces indicated on the map; these are the minor faction systems. If Keleres is a minor faction, choose one of its three possible home systems at random. If The Firmament/Obsidian is a minor faction, randomly choose which side of its home system to use; this will determine whether the Firmament or Obsidian alliance card is granted by Minor Factions.
• "Red vs Blue": a 2v2 alliance mode deathmatch. The Prophecy of Kings expansion is required. The players on the galactic west ("Roll For Initiative" and "The Cheeky Rift") are a team, facing off against the players on galactic east ("If I Only Had A" and "Once Upon A War Sun"). Each team only has two kinds of technology specialties nearby.
• "Legendary": an off-balance six-player arena aimed at driving players toward the galactic center and making them fight for every last scrap. The Prophecy of Kings expansion is required. Unlike a standard map, the systems equidistant from players' home systems—all legendaries, coincidentally—are in the center ring.

Clarifications

This section includes clarifications about timings, interactions, and easily overlooked rules. If the players have a question, they should look here or consult the Living Rules Reference online.

• Space Stations (system tiles): A system that contains a space station and no planets gets a frontier token during setup when playing with Prophecy of Kings.
• Gravity Rift (anomaly): 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.
• Thunder's Edge (planet): When Thunder's Edge is placed into a system that contains a frontier token, do not remove the frontier token; it can still be explored as normal.
• Warfare (strategy card): If a tactical action that is part of the Warfare primary is canceled, or the resolving player's turn is ended, the rest of the strategy card is still resolved.
• Abilities (general): An ability that is unresolved cannot be triggered again within a timing window that is generated by itself.
• Executive Order (Keleres faction technology): Agendas that refer to "This Agenda Phase" remain in play and are resolved during that game round's Agenda phase, or if that round does not have an Agenda phase, the next Agenda phase that is resolved.
• Plot cards (Firmament faction ability): Once the game starts, the Firmament's Plot cards are hidden information. Players can look at the plot cards before the game begins, however.
• Cronos and Tallin (Firmament home system): When the Firmament's home system is flipped, units on Cronos are placed on Cronos Hollow. Units on Tallin are placed on Tallin Hollow. Units in the space area remain in the space area.
• Firmament/Obsidian (faction technologies): While these technologies cannot be researched once The Firmament has become The Obsidian, they can be gained directly by game effects that specify "gain."

Thunder's Edge Expedition Quick Reference

The printed quick reference repeats the six expedition costs listed under Thunder's Edge Expedition above: spend 5 resources; discard 1 unscored secret objective; discard 2 action cards; exhaust 1 technology specialty planet; spend 5 influence; spend 3 trade goods.