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Mech Rules

The helmsman and various other archetypes gain access to a specialized construct suit called a mech.

At first level, the pilot chooses one of the following body types for his mech: agile, bipedal, or quadruped/treaded.

A pilot must choose a mech body type that is at least their size or larger. All damage dealt to the pilot is evenly split with his mech (any excess damage from an odd number applies to the mech); if the mech is reduced to 0 hit points, it enters a state of critical failure and the pilot is automatically ejected. Mech’s can be repaired at a rate of 5 hp per day using a DC 10 Craft (mechanical) check. For each 5 points by which the pilot exceeds this DC, the mech recovers an additional 5 hit points. Climbing into a mech and activating it for combat is a full round action. Exiting the mech can be done as a move action.

Starting at 3rd level, a pilot can alter their choice of body type by spending a number of hours equal to the mech’s hit die plus ½ the number of enhancements on the mech (rounded down) rebuilding it. The mech is not available for use and is completely nonfunctional during this time.

Whenever the mech pilot changes his mech body type, he can also choose to exchange his existing enhancements, selecting new mech enhancements during this rebuild. Once this process is started, the mech is not available for use until this process is complete. A mech that is lost or destroyed can be replaced with 24 hours of uninterrupted work in a garage or similar environment where basic machining tools can be accessed.

Mechs grant a bonus to the pilot’s physical statistics as described in their entry and use the pilot’s mental statistics; unpiloted or remotely piloted mechs instead have Strength and Dexterity scores equal to 10 + the listed bonus. Mechs never have a Constitution or Intelligence score. Mechs use their pilot’s base attack bonus, saving throw modifiers, proficiencies, and skill modifiers. Mechs are not true living creatures, despite being treated as such in some ways, and do not gain feats or skill points of their own. Mechs cannot take actions on their own, and instead use the pilot’s actions. Much like objects and vehicles, mechs have a hardness score (as determined by their pilot’s level or their stat block), and take half damage from most energy attacks.

While piloting a mech, a character cannot wear armor or bulky clothing; the suits have numerous ports that need minimal obstruction between them and the pilot’s flesh to function properly. Due to the fact that the pilot is enclosed within the mech, he also cannot benefit from items that increase his own armor class, such as an amulet of natural armor or bracers of armor. While mechs have an armor bonus to AC, they generally do not cause arcane spell failure (though some options may change this).

They do, however, count as wearing metal armor for class restrictions such as those of the druid and monk. His mech can still be targeted by spells and effects that increase its defenses. A character cannot occupy a mech whose size is smaller than his own.

Weapon Affinity and Weapon Slots: Various mech body types are designed for certain types of weapons; this is called Weapon Affinity and affects the types of weapons a mech can wield. Any standard weapon (such as a longsword, crossbow, or even firearms such as pistols, revolvers, or shotguns) can be converted for use by a mech, though the weapon must be crafted in a size that the mech can use with its weapon slots. There are three types of affinities a mech can have: ranged, melee, and heavy. Ranged weapons include things like bows and one or two-handed firearms, while melee weapons include swords, hammers, axes, and similar weapons.

Heavy weapons include grenade launchers, rail guns, rocket launchers and similar weapons; the pilot of a mech with Weapon Affinity for heavy weapons is treated as having Exotic Weapon Proficiency (heavy weaponry) as long as they are piloting their mech.

A mech’s weapon slots are specially designed to seat a broad array of weaponry; one weapon slot can accommodate a single Medium or smaller sized weapon. A mech must have sufficient slots available and a weapon must be slotted for a mech and its pilot to wield it, unless otherwise noted. Multiple slots can be combined to fit larger weapons; two weapon slots fit a Large weapon, three slots fit a Huge weapon, 4 slots fit a Gargantuan weapon, and 5 slots can fit a Colossal weapon. Mechs never take inappropriately sized weapon penalties with slotted weapons. Attacks with slotted weapons are made using the pilot’s full base attack bonus, though they do not receive additional attacks for a high base attack bonus. If a mech attacks with a natural attack or unslotted melee weapon (such as a biped mech with the Arms enhancement), the mech takes a -5 to all attacks with slotted weapons.

BP (Battery Points): Starting at 2nd level, mechs gain a small pool of energy they can use to charge technological weapons and devices. When the mech activates a technological item or weapon, it may choose to have any consumed charges come from its battery pool instead. A mech restores battery points to its pool at a rate of 2 per hour.

Strength and Dexterity Bonus: Starting at 5th level, the mech gains a +2 enhancement bonus to its Strength and Dexterity scores. At 9th level and every four levels thereafter, this bonus increases by an additional +2.

Size Increase: At 11th level and again at 20th, the mech may be upgraded over 1 week’s time to increase by one size category, gaining a +4 size bonus to Strength and an additional 10 hit points, and incurring a -2 penalty to Dexterity and a -4 penalty to Stealth checks (the mech does not incur any additional penalties to Stealth due to size). These bonuses and penalties stack for each additional size increase the mech gains from the Size Increase racial ability or mech enhancements.

Alternatively, the mech can be kept the same size and instead increases its base Dexterity bonus by +2 and gains 10 additional hit points.

Mech Body Types

Agile

Starting Statistics

Size Small; Speed +20 ft.; AC +1 armor; Melee wing (secondary) x2 (1d4); Reach 5 ft.; Ability Scores Dex +4; Bonus HP 5 hp; Weapon Affinity ranged; Weapon Slots 1

5th level Advancement

Flight: The agile mech grants its pilot a fly speed of 20 feet with average maneuverability. Every 5 levels thereafter (10th, 15th, 20th) this speed increases by 10 feet and maneuverability increases by one step.

Hover: The mech can halt its movement while flying, allowing it to hover without needing to make a Fly skill check.

Biped

Starting Statistics

Size Medium; Speed as pilot; AC +2 armor; Melee slam (primary) x1 (1d6); Reach 5 ft.; Ability Scores Str +2, Dex +2; Bonus HP 10 hp; Weapon Affinity melee, ranged; Weapon Slots 2

Special: Bipeds start play with the Arms enhancement.

5th level Advancement

Shielded Limbs: The biped mech’s forelimbs are specially modified to provide additional protection to the pilot, granting him a +2 shield bonus to AC. This bonus increases by +1 every 5 levels thereafter (10th, 15th, 20th).

If the mech is already wielding a shield, he instead increases its shield bonus to AC by an amount equal to that granted by this ability -1.

Quadruped/Treaded

Starting Statistics

Size Large (-1 penalty to AC and attack rolls, +1 to CMB/CMD, -4 Stealth); Speed +10 ft.; AC +4 armor Attack Slam (primary) (1d8); Melee Reach 5 ft.; Ability Scores Str +4; Bonus HP 15 hp; Stability +4 racial bonus to their Combat Maneuver Defense when resisting a bull rush or trip attempt Weapon Affinity heavy; Weapon Slots 2

5th level Advancement

Heavy Weapons Array: Starting at 5th level and every 5 levels thereafter (10th, 15th, 20th), the quadruped mech gains an additional weapon slot at no additional cost.

Table 6: Mech Companion Base Statistics
Class Level Hit Dice Armor Bonus Hardness Str/Dex Bonus Special BP
1 1d10 0 1 0 Mech Enhancement 0
2 2d10 +1 2 0 2
3 3d10 +1 2 0 4
4 3d10 +2 3 0 6
5 4d10 +2 3 +2 Mech Enhancement 8
6 5d10 +3 5 +2 10
7 6d10 +3 5 +2 12
8 6d10 +4 7 +2 14
9 7d10 +4 7 +4 Mech Enhancement 16
10 8d10 +5 9 +4 18
11 9d10 +5 9 +4 Size Increase 20
12 9d10 +6 11 +4 22
13 10d10 +6 11 +6 Mech Enhancement 24
14 11d10 +7 13 +6 26
15 12d10 +7 13 +6 28
16 12d10 +8 15 +6 30
17 13d10 +8 15 +8 Mech Enhancement 32
18 14d10 +9 17 +8 34
19 15d10 +9 17 +8 36
20 15d10 +10 19 +8 Size Increase 38

Mech Enhancements

Descriptions follow below for the various enhancements that a character can apply to their mech to increase its combat and non-combat abilities.

Additional Weapon Affinity: The mech gains Weapon Affinity with an additional weapon type of your choice (melee, ranged, heavy). This enhancement can be taken up to two times, selecting a different weapon type each time.

Additional Weapon Slot: The mech gains an additional weapon slot. This enhancement can be taken multiple times.

Advanced Armor Plating: The mech increases its armor bonus to AC by +2. The mech must be at least 7th level to take this enhancement.

Advanced Munitions Upgrade: The mech is treated as though its pilot has Greater Weapon Specialization with one weapon it took the Munitions Upgrade Enhancement for. This enhancement can be taken multiple times but must apply to a different weapon each time. The mech must be at least 13th level to take this enhancement.

Advanced Targeting Upgrade: The mech is treated as though its pilot has Greater Weapon Focus with one weapon it took the Targeting Upgrade enhancement for. This enhancement can be taken multiple times but must apply to a different weapon each time. The mech must be at least 9th level to take this enhancement.

Arcforged Armor: The mech increases its hardness by 5. The mech must be at least 9th level to take this enhancement.

Arms: The mech gains a pair of fully integrated mechanical arms which allow it to wield an appropriately sized weapon without slotting it first. A mech may make as many attacks with such a weapon as their pilot’s base attack bonus would normally allow. While wielding a weapon in such a manner, the mech is treated as having two fewer weapon slots (minimum 0); any weapons currently occupying slots that would be made unavailable cannot be used while the weapon is in hand.

Cerebral Reinforcement: The mech extends the following construct features to its pilot while they operate it: Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns and phantasms). The mech must be at least 15th level to select this option.

Hover Stabilizers: Mechs with this ability gain slow fall, as the monk ability, except they do not need an adjacent surface to activate it. Treat the mech’s level as its monk level to determine the total distance negated by this ability. The mech must be a quadruped with the Powered Servomotors enhancement to choose this enhancement.

Intelligent Vessel: The mech is able to be controlled by AIs in a manner similar to a robot, gaining the aggregate template when it is so controlled (even though it is not a robot). The Mech does not, however, gain the benefits of any feats that the AI possesses. The mech starts out controlled by a base AI with 10 in all of its mental ability scores and the ability to speak one language the pilot is capable of speaking. If the pilot is not inside the mech, the AI can cause the mech to act on its own, taking a full round’s worth of actions each round.

Manual Loader: An allied character in an adjacent or shared square can reload your heavy weapons for you as a standard action, or firearm weapons for you as a move action.

Modified Aerodynamics: Mechs with this enhancement can make a DC 15 Fly check to fall safely from any height without taking falling damage, as if using feather fall. When falling safely, it may make an additional DC 15 Fly check to glide, moving 5 feet laterally for every 10 feet it falls. The mech must be a biped with the Powered Servomotors enhancement to choose this enhancement.

Munitions Upgrade: The mech is treated as though its pilot has Weapon Specialization with one weapon from a category it has Weapon Affinity with. This Enhancement can be taken multiple times but must apply to a different weapon each time. The mech must be at least 5th level to take this enhancement.

Nautical Superiority: The mech gains a swim speed equal to base land or fly speed chosen when this upgrade is selected. The mech can remain submerged for 1 hour per Hit Die before its air filters start to fail and the pilot has to make Constitution checks to hold their breath or begin drowning. A mech must be at least 5th level to take this enhancement.

Powered Servomotors: The mech is capable of fantastic feats of agility. Mechs with this enhancement gain a +15 bonus to Acrobatics or driver Ride checks made to perform a long jump or high jump. In addition, they are always considered to have a running start when jumping.

Shielded Cockpit: The mech extends the following construct features to its pilot while he operates it: Immunity to bleed, disease, death effects, necromancy effects, paralysis, poison, sleep effects, and stunning. The mech must be at least 13th level to select this option.

Size Increase: The mech increases by one size category, gaining the bonuses and penalties listed in the Size Increase racial ability. The mech must be at least 7th level to select this option.

Special: This mech enhancement may be taken one additional time by a mech of at least 17th level.

Sticky Treads: The mech gains a climb speed equal to half its movement speed. This enhancement can only be taken by mechs with the Quadraped/Treaded body type.

Superior Arcforged Armor: The mech increases its hardness by 5. This stacks with the increase granted by the Advanced Armor Plating enhancement. The mech must have the Advanced Armor Plating enhancement and must be at least 13th level to take this enhancement.

Superior Armor Plating: The mech increases its armor bonus to AC by +3. This stacks with the increase granted by the Advanced Armor Plating enhancement. The mech must have the Advanced Armor Plating enhancement and must be at least 11th level to take this enhancement.

Targeting Upgrade: The mech is treated as though its pilot has Weapon Focus with one weapon from a category it has Weapon Affinity with. This enhancement can be taken multiple times but must apply to a different weapon each time.

Thrusters: The mech increases their current fly speed by 10 feet and increase their maneuverability by one step. If the mech did not have a fly speed before taking this upgrade, it now has a maneuverability of clumsy. Each time it takes this enhancement, improve its fly speed by an additional 10 feet and its maneuverability by one step. This enhancement can be taken up to three times.

Weapons Upgrade: The mech can treat the damage dice of weapons from a category with which it has Weapon Affinity as though they were one size category larger. The mech can take this upgrade multiple times, but it cannot apply to a given weapon category more than once. A mech must be at least 5th level to take this enhancement.

Non-Companion Mechs and Vehicles

The rules presented for companion vehicles and mechs can also be used to generate vehicles and mechs for general use in your campaign world.

A character with the Craft Companion Vehicle feat and access to a garage or production lab can craft any of the vehicles detailed earlier. Crafting a vehicle requires a Craft (mechanical) check with a DC equal to 15 + the vehicle’s hit dice + the number of enhancements, and costs 800 pieces x (vehicle’s hit dice + total number of enhancements). Use the mech advancement table when determining the abilities of the crafted vehicle; a character cannot craft a vehicle in this manner whose required pilot level exceeds his total character level -4.

A character with the Craft Mech feat and access to a garage or military lab can craft any of the mech types detailed earlier. Crafting a mech requires a Craft (mechanical) check with a DC equal to 20 + the mech’s hit dice + the number of enhancements, and costs 1000 pieces x (mech’s hit dice + total number of enhancements). Use the mech advancement table when determining the abilities of the crafted mech; a character cannot craft a mech in this manner whose required pilot level exceeds his total character level -4.

Section 15: Copyright Notice

Arcforge: Technology Expanded © 2018, Legendary Games; Authors: Matt Daley, Michael Sayre.