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Mechs

Mech Overview

Source Tech Revolution pg. 92
Mechs are immense robots that combine armor, agility, and firepower into one devastating package piloted by one or more operators. In Starfinder, mechs represent powerful tools for PCs to confront far mightier foes than they could unaided. PCs might custom-build their own mechs, salvage the technology in the field, or pilot mechs provided by powerful patrons.

Building And Using Mechs

Source Tech Revolution pg. 92
Building Mechs (page 96) provides a system for constructing custom mechs and presents a wide array of options for players to customize their machine’s size, armaments, limbs, and more. The section also presents rules for multiple PCs to build an assembled mech, each create their own single-pilot mech, or split between several machines in any combination.
Mech combat (page 112) is a flexible system. Mechs use many of the existing rules for Starfinder, allowing players to jump into mech combat with ease, whether they’re taking on titanic creatures, clashing with enemy mechs, or fighting off entire squads of foes single-handedly. Unlike powered armor, which functions as an extension of the operator’s body that deflects attacks rather than absorbs damage, a mech functions more like a specialized vehicle that’s piloted by one or more operators. A mech has its own defenses and Hit Points, shielding its operators from harm while they give the mech commands (see page 98 for more information on mech statistics). Mech weapons (page 102) are in a class of their own, far exceeding in scale any armaments sized for PCs.
Much as with starships, acquiring or using mechs does not cost the PCs credits (in a typical campaign, mechs are not available for sale), and Starfinder campaigns can thrive with any amount of mech combat, from mech encounters every session to no mech combat whatsoever—the exact prevalence of mech encounters can be tailored to the campaign’s needs and is ultimately up to the GM to decide. Mechs provide a significant power advantage that make many otherwise challenging encounters trivial, so GMs should consider being purposeful on their inclusion—such as a means to overcome impossible odds or insurmountable foes—rather than to simply trivialize challenges the PCs face.

Assemble!

Source Tech Revolution pg. 92
Some groups playing in a mech-themed campaign might want several of their individual mechs to be able to combine into a larger, amalgamated mech that they can copilot as a party. If you decide that this fits your campaign, you can allow the PCs to design two sets of mechs (using the rules for building mechs starting on page 96): the individual, component mechs; and a singular mech to represent the assembled mech, which uses all the party’s Mech Points. The assembled mech should feature the weapons and systems of its component mechs, and its frame should be the same size category as the largest component mech.
Combining several mechs into an assembled mech (or disassembling an assembled mech into its component mechs) should generally take place only outside of combat; if the GM allows for in-combat mech assembly or disassembly, it takes at least one round.
Damage dealt to an assembled mech is carried over to its component mechs when it disassembles, and damage dealt to component mechs carries over to an assembled mech when they combine. To represent this, convert the mechs’ current HP to a percentage of total HP (rounding down to the nearest 10%) and apply it to the assembled or disassembled forms. For example, if three component mechs have a maximum collective total of 75 HP and have a collective current HP of 35, the mech they assemble into should have 50% of its total HP. If that assembled mech takes damage that reduces it to 40% of its total HP and then disassembles, the three component mechs should have a collective current HP of 40% (or 30) HP, divided among them such that no individual mech regains Hit Points from assembling or disassembling.

Sample Mechs

Source Tech Revolution pg. 92
Pages 112–119 present more than a dozen examples of mechs from cultures across the galaxy, such as the Azlanti Imperator Pinion, the Daimalko Valkor, the Idaran Breacher, and the Veskarium’s Warmander. The mechs detailed there are of course just examples; far stranger and rarer models are manufactured across the galaxy, as well as near-infinite custom-built mechs found throughout the Starfinder setting.

Designing Mech Encounters

Source Tech Revolution pg. 92
Mech combat uses the same rules and functions on the same scale as most other Starfinder combats, such as using square-grid maps, means of resolving attacks, and more. As a result, designing encounters involving mechs is not substantially different from designing any other combat encounter. The following are some things to consider when designing encounters for mechs.
CR: PCs that are operating mechs appropriate for their level have an Average Party Level 3 levels higher than normal, and therefore are able to overcome stronger threats as a result; consider the following when designing encounters for mechs: First, mechs with multiple operators are typically highly maneuverable, capable of both moving and attacking skillfully. As such, slow-moving foes with limited ranged options are less threatening for PCs operating mechs that can often run circles around them. When presenting a small number of foes, consider favoring maneuverable or long-range combatants, or consider providing terrain or objectives that encourage the PCs to engage the enemy at close range.
Second, many mech weapons excel at attacking multiple targets at once, so mechs excel at fending off large numbers of lesser foes. Enemies whose CR are lower than the mech’s tier rarely pose a threat to the mech, unless they’re in large groups. However, using only a few mechs to defeat a small army (or a large foe with numerous minions) can be extremely gratifying.
Experience: Even though the PCs can overcome much more powerful threats than usual in a mech, mech encounters should provide a similar amount of experience to encounters appropriate for the PCs’ APL. Combat encounters the PCs overcome while using mechs typically grant experience points as though the CR of each challenge were 3 lower than usual. Do not reduce the experience points earned from challenges that aren’t substantially affected by the PCs’ access to mechs, such as story awards for performing heists or overcoming encounters without mech combat.
Space: Mechs are big. Huge mechs may be able to navigate conventional adventure spaces, but Gargantuan and Colossal mechs require a larger area to maneuver and fight effectively. When creating mech encounters, aim to provide each mech at least four times as much area to maneuver in than the mech occupies, and make sure any paths, halls, or other passageways are large enough to accommodate all of the combatants. Alternatively, if the goal is to create an encounter where the mech is forced to struggle to maneuver or engage foes due to restrictive terrain, consider treating the encounter’s Challenge Rating as at least 1 lower. An encounter in which the PCs fight an immense foe by exploiting claustrophobic terrain can offer fun tactical challenges!
NPC Mechs: Nonplayer character mechs are built using a different set of guidelines to provide a balanced encounter for player characters. See page 109 for advice on building NPC mechs.

Transform!

Source Tech Revolution pg. 93
Another exciting possibility for mechs is giving them the ability to transform between a mech and a vehicle form. If this functionality fits the role of mechs in your campaign, you can allow for one or more vehicles obtained by the PCs (such as through purchases or adventure rewards) to transform into one or more mechs. Transforming mechs should be no more than one size category larger than their vehicle form (for example, a Huge vehicle might transform into a Huge or Gargantuan mech).
As with assembling mechs (page 92), such involved transformation should generally take place only outside of combat, and damage sustained in either mech or vehicle form should be retained between forms. As described in the Assemble! sidebar, convert HP to a percentage of total each time a transformation occurs and ensure that no mech or vehicle regains Hit Points merely by transforming. Effects that restore Hit Points to vehicles don't function on vehicles that can transform into mechs.