Inatmo Vehicle Combat

Vehicles are the atypical vehicles that one finds planetside. This section covers using vehicles in the tactical combat rules. Inatmo vehicle combat covers how to shoot from, shoot at, and destroy vehicles in battle. Inatmo vehicle combat is cinematic vehicle combat and is persona centered. This section is for when lethal personal combat combines with driving. Before destroying vehicles, you should learn how to create them first. Jump to Inatmo Vehicle.

Inatmo vehicle combat works best for land-based combat. These rules can accommodate air, water and submariner combat. This section does not apply to combat taking place exterior to the atmosphere. For spacecraft combat, jump to Spacecraft Combat.

This section is not for expeditions driving from one place to another. This section is not for expeditions racing cars for fun. This section is not for drivers who are behaving recklessly. For uncombat driving shenanigans jump to Driving.

Multilane flying car chase scene with guns akimbo.

Seat belts please.

Table Top

Most vehicles will run out of tabletop hex mat in a unit or two. Managing the high movement rates of vehicles in combat is a hex mat challenge. A typical vehicle will cross an entire hex max in one combat unit. When using tokens and hexagons, full-speed vehicles just zip across the field.

Vehicle racing, or chasing, is another reason to keep track of vehicle location. Car chases are fun. If there are no persona tokens on the mat, try a smaller scale hex mat. The smaller scale mat allows for high-speed maneuvers, movement and treacherous obstacles. Regardless of the reason for tracking vehicles on a hex mat, they move like any other persona. They just cover more hexes each unit and can have a collision if reckless.

Players with flying vehicles must keep track of their elevation. EXP is not responsible for misuse of the Pythagorean theorem.

Typical Use Cases

Inatmo vehicle combat is an extension of the tactical combat rules. Attack rolls, movement, and damage parallel the tactical system. The ruleset here is for tactical combat, including moving vehicles. The main challenge for vehicle combat is accommodating relative movement rates. Inatmo combat focuses on the most common use cases that occur in vehicle combat.

Parked vehicles are cover or concealment.
Common Combat Situations
  • Attack roll targeting a moving vehicle (attacker essentially still)

  • Attack roll from a moving vehicle (target essentially still)

  • Attack roll between moving vehicles (attacker and target moving)

  • Additional considerations

Speed

A vehicle moving at twenty h/u or less is moving too slow for vehicle combat. This movement rate works within the tactical combat system. The vehicle becomes mobile cover or concealment and not something that requires a whole combat section.

Vehicle combat is persona-focused and cinematic. The vehicle combat ruleset is faux realistic and designed for dice-rolling fun.

Observations on Speed
  • 1 h/u = 1 m/s

  • 1 h/u = 3.6 kmh

  • 1 h/u = 2.2 mph

  • 10 h/u = fastest mundane terran

  • 25 h/u = gale force winds

  • 28 h/u = 100 kmh or 60 mph

  • 31 h/u = mundane terran spotted cat

  • 45 h/u = 100 mph or 160 kmh

  • 80 h/u = speed of an arrow

  • 250 h/u = speed of pistol bullet

  • 342 h/u = speed of sound or Mach 1

Stationary Attacker

The main challenge for the attacker is that their target is moving at high speed. The persona launching the attack is relatively motionless, and only the movement rate of the vehicle applies. The speed of the vehicle makes a successful attack roll more difficult. The greater the speed differential, the harder it is to hit the target. The speed of the vehicle adjusts its Defence Rating.

Speed Attack Penalty

Attack Roll - 10 per h/u

Attack Roll = 500 (kilodie) - (30 h/u * 10) = 500 - 300 = 200
The attacker can add their Skilled or Raw Bonus to this roll.

Moving Attacker

The main challenge for the attacker is that they are moving at high speed. The target is relatively motionless, and only the movement rate of the vehicle applies. The speed of the vehicle makes a successful attack roll more difficult. The greater the speed differential, the harder it is to hit the target. The speed of the vehicle improves the Defence Rating of the stationary target.

Speeder Attack Penalty

Attack Roll - 15 per h/u

Attack Roll = 500 (kilodie) - (30 h/u * 15) = 500 - 450 = 50
The attacker can add their Skilled or Raw Bonus to this roll.

Attacking from a vehicle moving 25 h/u is equivalent to attacking through a gale-force wind. Attacking from a vehicle moving 45 h/u is equivalent to attacking through 100 mph wind.

All Moving

The challenge for attackers includes speed differential, drag, vibration, and evasive maneuvers. These conditions make a successful attack roll more difficult. The greater the relative speed of the two vehicles, the more difficult it is to score a hit. The slower moving vehicle has less penalties.

The following demonstrates the attack roll penalties between vehicle Eh going 30 h/u and vehicle Bee going 50 h/u

All Moving Speeding Attack Penalty

Attack Roll - 5 per h/u

Speeding Attack Penalty for attackers in Eh = (30 h/u * 5) = 150
Speeding Attack Penalty for attackers in Bee = (50 h/u * 5) = 250

All Moving Speeder Attack Penalty

Attack Roll - 10 per h/u differential

Differential = Bee Speed - Eh Speed = 50 - 30 = 20
Faster Attack Penalty = (20 h/u * 10) = 200
Bee’s attack penalty is worse at -450.

It is much harder for attackers from the higher speed vehicle (-450) to attack the slower speed vehicle (-150).

Defence Rating

Vehicle Defence Rating is 500

Vehicles do not have armour unless otherwise specified. Most vehicles are easy to hit, but hard to damage. The defence rating represents the attack roll needed to damage a target. That roll is difference from actually hitting a target.

The Defence Rating of a target inside a vehicle is different yet again. A target inside a vehicle has it’s own defence rating. This defence rating is likely improved by partial cover and concealment from their ride.

Flanking

We do not bother with flanking in vehicle combat. There is no advantage to flanking when vehicles are entirely randomly created. A vehicle’s flank could be as forbidding as its bow.

Vehicle Damage

A successful attack roll on a vehicle indicates damage. Vehicles do not have hit points and are damaged differently from organic personas. Vehicles have a random damage location like robots and spacecraft.

Breaking Down Vehicle Breakage
  1. A successful attack roll

  2. Location

  3. Severity

  4. Effect

Location

Hitting the vehicle with a rock, bullet or lazer beam will damage a random location. The premise of the random location is the same for all inorganic damage location charts. The system damaged may be some distance from the damage point. Ricochets, power surges and force distribution essentially make the damage location random.

Vehicle Damage Location Table
What got done broke from smash.

Die Roll (1d100)

System Damage

Effect

01-12

Locomotion

Speed and handling level

13-24

Cargo/Crew

Space Reduced, cargo damage, target crew

25-36

Engine

Acceleration and speed

37-48

Fuel

Range

49-60

Speed System

Speed

61-72

Acceleration

Acceleration

73-84

Steering System

Handling level

85-99

Accessory

Random accessory.

00

Ref’s Own Table

Die Roll

System Damage

Effect

If the vehicle does not have the location generated the player can roll again, or move to nearest damageable hit location.

Extent

The extent of damage is determined randomly and modified by the hit points of the damage delivered. Since vehicles and vehicle components don’t have HPS, they suffer reduced efficiency when damaged.

Extent of Damage Table
How severe a blow did the system receive?

Die Roll (1d100)

Descriptor

Drop

Multiplier

01-10

Trivial

0%

1

11-60

Minor

10%

0.9

61-90

Major

40%

0.6

91-99

Critical

70%

0.3

00

Cataclysmic

99%

0.01

Die Roll

Descriptor

Drop

Multiplier

Force bonus rules make cataclysmic system damage rolls more common.

Force Bonus

The extent of damage is modified upwards by the HPS of damage inflicted on the system. For example, 15 HPS of damage would increase the extent of damage roll by 15. If the player rolls 08 on the 1d100 roll with 15 hit points of damage, she moves the extent of damage from Trivial to Minor.

Referees may wish to adjust the amount of damage even further. For every 75 HPS in damage, the attacker makes an additional extent of damage roll. Thus a single attack that inflicts 230 HPs in damage to the vehicle would make three extent of damage rolls at +75 and one roll at +5. A fusion grenade attack could damage every component on a vehicle and not just destroy a single component. MUltiple damage rolls allows big hit point totals to do big damage. Big HPS Big Damage rules are optional.

Cumulative Destruction

The damaging effects of successful attacks are cumulative. A vehicle system can become disabled over several attacks. A system taking two major damage (40% performance drop) is now functioning at 36%. For example, a vehicle’s speed would be reduced from 100 kmh to 36 kmh.

A system is disabled when it is reduced to less than 10% function.

Instantaneous destruction occurs when an attack destroys a system in a single blow. The attack must drop the system from 100% to <1% function in a single attack.

Damage Descriptors

Each time a system is damaged, its performance decreases. The damage descriptors offer another way to describe net damage. A system with minor damage is functioning at 90% capacity. A system with less than 10% of capacity if disable.

Descriptor of Component Damage
How badly is the part broke?

Percent Function

Function Descriptor

100

Fully Operational

91-99

Minor Damage

31-90

Major Damage

11-30

Critical Damage

1-10

Disabled

<1

Destroyed

Percent Function

Function Descriptor

Hull DEF is destroyed when AR < 420.

Targeting Components

Players often want to "shoot out the tires" of a vehicle. Vehicles in EXP are randomly created and do not follow mundane terran car tropes. To target a specific component of a vehicle (like tires, or engine) the persona must know the vehicle, and have Combat Driving Skills. This rule applies to moving vehicles in combat, not when vandalizing the neighbour’s car.

The player may move her Vehicle Hit location up or down the table depending on her Combat Driving Skill. Combat Driving 1 would allow the player to move her random hit location of fuel to either speed or engine.

Targeting Passengers

Players often want to "shoot the driver" of a vehicle. Vehicles in EXP are randomly created and do not follow mundane terran car tropes. To target a specific passenger a vehicle the attacker must know the vehicle, and have Combat Driving Skills. This rule applies to moving vehicles in combat, not when ambushing a car stopped at a drive thru.

As with targeting components player may move her Vehicle Hit location up or down the table depending on her Combat Driving Skill. Combat Driving 1 would allow the player to move her random hit location Locomotion or Engine into the Crew space. This would allow the player to make an attack roll on a random passenger in the crew space. However with the right weapon (grenade or aerosol) every target in the crew space may be damaged.

To directly target a specific passenger in a moving vehicle during combat is incredibly difficult. The player would first have to score a hit on the Cargo Crew area and then target that persona’s defence rating applying cover penalties. Only an attacker with Combat driving, weapon skills, high level and special scope support will find this possible.

Humanoid woman firing lazer cannon through canopy of vehicle.

Rear gunner.

Driving Skills

Driving skill is not combat driving skill. Driving skill and handling class will keep the vehicle from crashing during combat. Driving skill may allow the expedition to make zany maneuvers without crashing their vehicle. Mundane driving skill does not improve attack rolls or defence ratings.

Combat driving skill can be used to improve a player’s attack roll, or protect a vehicle from attack. The driver can transfer her combat driving skill to any other persona doing combat in the vehicle. Combat driving skills may be covered elsewhere, but in this section the players get +42 on attack rolls and +2 on Task rolls for each skill level.

To learn collision avoidance rules jump to Driving.

Attack Types

The wind drag surrounding speeding vehicles has an impact on every attack type. The Attack Roll penalty for speed combines all the challenges into one faux realistic value.

Strike Weapons

Nope. Strike weapons are self-powered thrusting and striking weapons. Attacks with swords, axes, or lances are usually precluded by range in vehicle combat. Strike weapons used against high speed vehicles will usually result in a pedestrian collision before vehicle damage.

Fling Weapons

Nope. Fling attacks are self-powered projectile attacks. Arrows, axes, and shuriken cannot compete with the winds of high-speed vehicles. The attack roll penalty for speed effectively eliminates all Fling attacks from vehicles.

Shoot Weapons

Shoot weapons are powered projectile attacks. It is assumed that personas fighting between moving vehicles are using shoot weapons. These attack types are still subject to enormous penalties due to differentials, vibrations and wind drag. Individual weapons may reduce the penalties applied due to the wind effect. For example, a lazer or energy weapon is much less affected by air turbulence than a bullet.

Area Weapons

Area weapons are grenades and aerosols. Area of effect attacks must score a hit on the vehicle to inflict damage. Typically Area weapons need only target a specific hex. In vehicle combat the Area Attack Roll must beat the vehicle’s Defence Rating.

Vehicle Weapons

These are bespoke combat accessories baked into the inatmo vehicle. Vehicle weapons are generated during vehicle fabrication. Built-in vehicular weapons may have gimbals, servos, and software to compensate for high-speed combat. These components significantly reduce the penalties suffered due to drag and speed differential.

Baked-in Bang Bang Benefits
  1. Speeder and Speeding Penalties are reduced to -5 per h/u

  2. Baked in weapon plus Vehicle Combat Skill eliminates all penalties.

Ramming

Ramming involves an intentional collision between two vehicles. Or the intentional collision between a vehicle and a persona. Mutual ramming happens automatically, and the vehicles and passengers are damaged.

Params of the Ram Rams
  1. Ramming vehicle must be faster or

  2. Ramming vehicle has intercept path

  3. Ramming vehicle must make an Attack Roll

  4. Target vehicle can avoid with Driving Roll

  5. Collision result as per Driving

Boarding

Jumping onto a moving vehicle is fraught with risk. Without special effects and camera speed adjustments, boarding is nearly impossible. Nevertheless, players will want to have their personas board moving vehicles.

Params of Boarding
  1. Navigate to jump range Driving

  2. Attack Roll as Strike Attack

    1. Win attack roll

      1. Pedestrian struck at differential speed (remember head on speed is different)

      2. If survives = successful boarding

    2. Miss attack roll

      1. Pedestrian thrown at differential speed (remember head on speed is different)