# ORBITAL ASSAULT ## A Supplement for Warhammer: The Horus Heresy — Age of Darkness *Version 2.0 — built as a sibling to the Zone Mortalis supplement.* ### Foreword The Age of Darkness Orbital Assault rules allow players to recreate the thunderous opening hours of a planetary war — the moment drop pods crack open, gunships scream from a burning sky, and a prepared garrison meets the first wave of a Legion descent. Where Zone Mortalis is the war in the corridors and Hive War the war in the streets, Orbital Assault is the war that begins it: a single, decisive descent onto fortified ground. These rules are a supplemental addition to the *Warhammer: The Horus Heresy — Age of Darkness* Rulebook. > **'Core' and 'Expanded' Rules** > > All of the rules in this document are **Expanded Rules**. --- ## The Orbital Assault Battle An Orbital Assault is **asymmetric**. One player is the **Attacker**, whose entire force descends from orbit. The other is the **Defender**, who holds prepared positions and deploys normally. All standard *Age of Darkness* rules apply except where noted here. Where this document is silent, the core rules apply. ### The Defender's Preparations The Defender shapes the battlefield. They place all terrain (the Attacker places none) and prepare their positions using rules that already exist — no reinventing required: - **Fortifications** use the **Battlefield Fortifications** rules from *Legacies of the Age of Darkness* (the Fortification Type, with the Emplacement, Bunker and Structure sub-types). The Defender may include a **Battlefield Fortifications Detachment** as an Additional Detachment, exactly as those rules describe, and deploys them first (before any other models). Fortifications such as the **Vengeance Weapon Battery**, **Firestorm Redoubt**, **Aquila Strongpoint** and **Fortress of Redemption** are ideal here — the latter two carry the **Orbital Defense** rule, which punishes drop pods and orbital craft arriving within range (see Planetfall, below). - **Barricades.** To reflect a dug-in garrison, the Defender begins the Battle with a **free Aegis Defence Line** (1 Core Platform and 6 Aegis Barricades, per the Legacies profile), deployed with their fortifications. Infantry or Paragon models in contact with an Aegis Barricade gain a **5+ Cover Save**; barricades don't block Line of Sight and are crossed as Difficult Terrain. The Defender may of course buy more. - **Battlefield Assets** are always in use (see below). The Defender invests in defensive Assets; the Attacker in Assets that smooth the descent. --- ## Orbital Assault Special Rules These few rules account for the particular method of this war. They are the heart of the supplement — everything else is the core game. ### Planetfall *(the Attacker's deployment)* The entire Attacker force begins in **Reserve**. Attacker units arrive by **Deep Strike**, entering from anywhere on the Battlefield per the core Deep Strike rule, or may instead walk on from the Attacker's table edge. The Attacker takes the first turn. ### Drop Assault Doctrine The method of orbital war loosens the normal restrictions on a descending force: - **Terminator Descent.** In an Orbital Assault, any Attacker unit composed entirely of models in Terminator plate (the Cataphractii, Tartaros, or equivalent Terminator armour profiles) may use the **Deep Strike** special rule, even if it does not normally have it. - **Drop and Charge.** A unit that **natively** has the Deep Strike special rule (printed on its profile, not merely granted by Terminator Descent) may declare a **Charge in the same turn it arrives by Deep Strike**. This is an exception to the core rule preventing charges after arriving from Reserve. ### Disrupted Drop *Auspex-masters and tech-priests flood the approach with scrambling returns and false locator pings, turning a precise descent into a scattered, lethal mess.* While an enemy model with the profile of a **Master of Signals, Forge Lord, Techmarine, or Magos / Archmagos** is on the Battlefield, any opposing unit arriving by **Deep Strike** with its first model placed **within 12"** of one or more such models must make a **Scatter Roll** before the rest of the unit is placed: > Roll the Scatter dice and 2D6. On an arrow, move the first model placed that many inches in the indicated direction; on a **Hit!**, it does not move. Then place the remainder of the unit within Unit Coherency as normal. Any model that cannot be legally placed is Removed as a Casualty (per the Deep Strike rule). This overrides any rule that would otherwise prevent the unit from scattering (such as a teleport homer or beacon). If a unit is within 12" of such models from more than one enemy, it still only scatters once. ### Orbital Barrage *The closing salvo of the fleet bombardment, walked across the ground before the boots arrive.* Immediately before the first turn, the Attacker makes a number of barrage strikes equal to **half the number of objectives, rounding up**. For each strike, nominate a point anywhere on the table and roll a D6: - **1:** Misfire — no effect. - **2–3:** Off-target — make a Scatter Roll (Scatter dice + 2D6), then resolve from the new point. - **4–6:** Direct Hit — resolve from the nominated point. **Barrage profile:** R —, FP 1, RS 9, AP 2, D 2, **Barrage, Blast (5")**. No Cover Save may be taken against it. Every model under the marker takes a hit, and any unit that takes one or more hits must make a **Cool Check** or gain the **Pinned** status. A Direct Hit centred on terrain other than a Fortification removes that terrain and replaces it with a **Crater** (a 5" Difficult Terrain marker). A Direct Hit centred on a Fortification inflicts **1 automatic Glancing Hit**. ### Game Length The Battle lasts **five Battle Turns**, then use the **Random Game Length** rule (roll at the end of Turn 5 and Turn 6; on a 3+ the Battle continues, otherwise it ends; Turn 7 is always the last). --- ## New Battlefield Assets — Orbital Assault The following Assets follow all the standard Battlefield Asset rules (Asset Points by points limit; the Attacker/Defender/Explosive/Minefield traits) and may be taken alongside the standard list whenever Battlefield Assets are in use. They are themed to the descent. ### Drop Beacon *(Attacker)* — 2 Asset Points *A homing transponder hurled down with the first wave.* - **Set-up:** Placed at the start of the Deploy Armies Step, more than 6" from any enemy Deployment Zone. - **Effect:** An Attacker unit arriving by Deep Strike may place its first model within 3" of this Marker instead of anywhere on the Battlefield. (Note: this does not stop a Disrupted Drop scatter if an enemy auspex-master is within 12".) At the end of each Battle Turn, roll a D6; on a 1, remove the Marker. ### Orbital Targeting Relay *(Attacker)* — 2 Asset Points *A ground spotter feeding corrections to the guns above.* - **Set-up:** Placed at the start of the Deploy Armies Step, anywhere in the Attacker's half of the table. - **Effect:** Once per Battle, at the start of any Attacker turn, the Attacker may call a single additional Orbital Barrage strike (resolved using the Orbital Barrage rule). While this Marker is on the table, the Attacker may also re-roll the Scatter Roll for one off-target barrage strike per turn. If any enemy model ends a move within 3" of this Marker, remove it. ### Augury Web *(Defender)* — 2 Asset Points *A lattice of scanners that turns the sky into a wall of warning returns.* - **Set-up:** Placed at the end of the Prepare the Battlefield Step, within the Defender's Deployment Zone. - **Effect:** Any enemy unit arriving by Deep Strike with its first model within **9"** of this Marker must make a Scatter Roll (Scatter dice + 2D6) before the rest of the unit is placed, exactly as the Disrupted Drop rule. At the end of each Battle Turn, roll a D6; on a 1, remove the Marker. ### Automated Bastion Gun *(Defender)* — 3 Asset Points *A stripped Tarantula chassis slaved to a fixed arc, firing on anything that breaks cover.* - **Set-up:** Placed at the end of the Prepare the Battlefield Step, within the Defender's Deployment Zone. Declare a 90° Fire Arc. - **Profile:** R 36", FP 3, RS 5, AP 4, D 1, Rending (6+). Treat the gun as having Armour 10 and 1 Hull Point; a Penetrating Hit or any Destroyed result removes it. - **Effect:** At the start of the Defender's Shooting phase, before any other shooting, the gun makes one Shooting Attack at **BS 4+** against the nearest visible enemy unit within its Fire Arc. It may not move or make Reactions. ### Pre-Sighted Killing Ground *(Defender)* — 1 Asset Point *Every metre of this approach has been ranged, marked, and zeroed.* - **Set-up:** Place the Marker at the end of the Prepare the Battlefield Step, more than 12" from the Defender's Deployment Zone. - **Effect:** Defender units making a Shooting Attack against an enemy unit with any model within 6" of this Marker may **re-roll Hit Test results of 1**. The Marker is permanent. ### Reinforced Redoubt *(Defender)* — 2 Asset Points *Additional ferrocrete and ablative plating poured over a key strongpoint.* - **Set-up:** During the Deploy Armies Step, assign this Marker to one Building the Defender garrisons. - **Effect:** That Building gains **+1 Armour** and the first **Penetrating Hit** it would suffer is treated as a **Glancing Hit** instead. Once this benefit is used, remove the Marker. --- ## Orbital Assault Mission Pack These Missions are intended as Primary Missions and follow the same shape as the Zone Mortalis Missions. Complete each Step in order. ### Mission Sequence 1. Determine Attacker and Defender (roll off; winner chooses role). 2. Select Mission (agree, or roll: 1–2 Planetfall, 3–4 Decapitation, 5–6 Break the Line). 3. Select Armies and Battlefield Assets (standard points limit; Assets always in use). 4. Prepare the Battlefield (Defender places all terrain, Barricades, and end-of-step Assets; nominates a Primary Edge — the opposite is the Attacker's Edge). 5. Deploy Objectives (Defender places; odd number per the Mission; none within 6" of another or a table edge). 6. Defender Deploys (entire force; may hold up to one unit per 500 pts in Reserve, entering from the Primary Edge). 7. Deploy-step Assets and Drop Beacons placed. 8. Orbital Barrage. 9. Play the Mission (Attacker takes the first turn; all Attacker units in Reserve). 10. Decide Victor. ### Mission Special Rules (all Missions) Planetfall, Drop Assault Doctrine, Disrupted Drop, Orbital Barrage, Reserves, Seize the Initiative. ### Controlling Objectives A unit controls an objective if it has one or more models within **3"** and is not Pinned, Suppressed, Stunned, Routed, or Locked in Combat. Contested objectives (eligible units from both sides within 3") are decided by **Tactical Strength**, exactly as the Core Missions (models within 3" × their Line (X) and Bulky (X) values). At game end the player controlling more objectives wins; ties are broken by the number of enemy units Removed as Casualties. --- ### Mission One — Planetfall *Seize a beachhead; hold every position.* - **Objectives:** 5, placed by the Defender. - **Set-up:** Defender deploys anywhere; Attacker entirely in Reserve. - **Victory:** Most objectives controlled at game end. Plus Slay the Warlord (2), First Strike (1). ### Mission Two — Decapitation *One position matters more than the rest.* - **Objectives:** 3 — the Defender designates one garrisoned Building near the centre as the **Command Node**, worth **3**; the other two are placed normally (1 each). - **Set-up:** Defender deploys anywhere; Attacker entirely in Reserve. The Attacker controls the Command Node only with a model **inside** the Building at game end. - **Victory:** Most objective Victory Points. Plus Slay the Warlord (2). ### Mission Three — Break the Line *Storm the wall before the guns range in.* - **Objectives:** Each Barricade and each garrisoned Building in the Defender's half is an objective worth 1. - **Set-up:** Defender deploys within 18" of the Primary Edge; Attacker entirely in Reserve. - **Victory:** The Attacker scores 1 VP for each such position they control at game end; the Defender scores 1 VP for each they still hold. Highest total wins. Plus Last Man Standing (1). --- ## Appendix — Quick Reference **Sequence:** Roles → Mission → Armies + Assets → Defender terrain/Barricades/Assets → Objectives (odd) → Defender deploys → Beacons/Assets → Orbital Barrage → Attacker turn 1 → decide victor. **Defender starts with:** core Building profiles for fortifications + **1 Barricade per 500 pts** (5+ Cover) + Battlefield Assets. **Drop Assault Doctrine:** Terminator units may Deep Strike. Units that natively have Deep Strike may **charge** the turn they arrive. **Disrupted Drop:** enemy Deep Strike within 12" of a Master of Signals / Forge Lord / Techmarine / Magos must Scatter Roll (Scatter dice + 2D6); overrides homers/beacons. **Orbital Barrage:** strikes = objectives ÷ 2 (round up). 1 misfire / 2–3 scatter / 4–6 direct. R —, FP 1, RS 9, AP 2, D 2, Barrage, Blast (5"), no Cover. Hit unit → Cool Check or Pinned. Direct hit: terrain → Crater; Building → 1 Glancing Hit. **Status checks (HH3):** Pinned / Suppressed / Stunned → **Cool Check**. Routed / Panic → **Leadership Check**. **Game length:** 5 turns, then Random Game Length (3+ continues at end of Turn 5 and 6; Turn 7 always last). **Objectives:** control within 3" (not Pinned/Suppressed/Stunned/Routed/Locked); contested by Tactical Strength. Tie → most enemy units destroyed. **New Assets:** Drop Beacon (A, 2), Orbital Targeting Relay (A, 2), Augury Web (D, 2), Automated Bastion Gun (D, 3), Pre-Sighted Killing Ground (D, 1), Reinforced Redoubt (D, 2). --- *A companion to the Zone Mortalis and Hive War supplements. Together they form the* **Siege of the Hive** *campaign system.*