The short answer
Cyberware slots are a compatibility and capacity problem, not a single pool you spend across the whole character. Start with the category, find the foundation when that category requires one, then count only the compatible options that fit inside it. An option can fail because it needs the wrong body location, requires a missing foundation, consumes more capacity than remains, must be paired, or simply does not stack with the copy already installed.
The reliable habit is simple: read the foundation first, then the option, then the exception line. That saves a player from buying a striking piece of chrome that cannot fit the character they have already built.
Hot take
Do not fill every available slot just because it is empty.
Capacity is where a build becomes recognizable. Leave room for the one future upgrade that changes how the crew handles a job, instead of spending it on a collection of small bonuses that never create a new plan. The caveat is that a campaign with frequent downtime and easy clinics may support a denser build. Even there, buy toward a role at the table, not toward an abstractly "complete" body.
First, identify the capacity you are actually using
The Core Rulebook divides cyberware into categories. Most categories that support options begin with a foundational implant; its slots hold compatible choices from that category. Neuralware, Cyberoptics, Cyberaudio, and Cyberlimbs all work this way.
| Foundation | Option Slots | What the entry adds |
|---|---|---|
| Neural Link | 5 | Required for Neuralware and the Subdermal Grip. |
| Cybereye | 3 per eye | Some options must be paired across two Cybereyes. |
| Cyberaudio Suite | 3 | You cannot install more than one. |
| Cyberarm | 4 | Includes a Standard Hand that takes no slot and costs no Humanity. |
| Cyberleg | 3 | Includes a Standard Foot; most leg options must be paired. |
Fashionware, Internal Body Cyberware, and External Body Cyberware work differently. They do not begin with one mandatory foundation, but each category is capped at 7 Option Slots. They are separate pools, so a spare internal slot does not create room for an external upgrade.
| Build question | Check first | Why it matters |
|---|---|---|
| Which part of the character is changing? | The item's cyberware category. | Categories do not share a universal pool. |
| Does the option name a prerequisite? | The required foundation or prior option. | An available-looking item may be illegal without it. |
| How much capacity does it use? | The item's exact entry. | Some options consume more than the usual amount. |
| Does it need a pair? | The option's pairing language. | Both installations, capacity use, and Humanity Loss matter. |
| Does the benefit repeat? | The stacking language. | A duplicate is not automatically useful. |
Read the Cyberware Guide alongside the source entry for the broader process: prerequisites, Humanity Loss, installation level, money, and downtime all belong in the same decision.
Foundation before option
Treat a foundation as a container with a purpose. The table above says which foundation holds what. The harder question is how much of that container a given option eats.
Unless an entry says otherwise, an option takes one slot. The bigger ones add up fast in a 4-slot Cyberarm: popup weapons and the Techscanner or Medscanner take 2 each, while the arm Cyberdeck and Popup Shield take 3. A MicroVideo takes 2 of a Cybereye's 3 slots, and a Dartgun takes all 3. A few items need a foundation but use no slot at all, such as limb coverings and the Sensor Array, which lets a Cyberaudio Suite hold up to 5 more options.
That creates a sequence:
- Choose the job pressure the character needs to answer.
- Find the category and foundation that enable the relevant option.
- Reserve the exact capacity the option consumes.
- Recheck any body-location, paired-installation, or related-prerequisite language.
- Only then decide whether the Humanity cost, installation setting, and campaign consequences are worth it.
Do not infer a prerequisite from an item's theme. A tool that looks like it belongs in an arm may follow a different rule than a tool that is explicitly a Cyberarm option. The source entry decides the category, not the picture in a catalog.
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Paired, standalone, and category-wide choices
Some cyberware options must be installed as a pair. The Core Rulebook calls that out directly for options that require two matching foundations: Low Light/Infrared/UV needs two Cybereyes and takes 2 slots in each, and Jump Boosters need two Cyberlegs and take 2 slots in each. A pair means buying the option twice, installing it twice, and paying Humanity Loss twice.
Other choices can be installed as the only cyberware in a meat limb. In the Core Rulebook that includes Big Knucks, Rippers, Scratchers, Slice 'N Dice, Wolvers, the Tool Hand, and the Subdermal Grip for arms, and the Talon Foot for legs. That is a listed exception, not evidence that every limb option works without a Cyberarm or Cyberleg. A Standard Hand installed in a meat arm does not count toward that one-piece limit. Standard hands and feet have their own rules; do not treat them as ordinary slot-using options.
Use this quick read before adding anything:
| If the entry says... | Your next action |
|---|---|
| "Requires" a named implant | Confirm that implant is already installed and has room. |
| "Takes" more than one slot | Reserve all of that capacity before shopping for anything else. |
| "Must be paired" | Plan two compatible foundations and two installations. |
| "Only piece in a meat limb" | Treat it as a listed exception, not a general limb rule. |
| "Does not stack" or is silent on stacking | Do not buy a duplicate for a second bonus. |
Stacking is an item rule, not a build assumption
The Core Rulebook's default is clear: benefits from multiple installations of the same cyberware do not stack unless the entry says otherwise. A second copy may be prohibited, may provide no additional effect, or may be useful only because the item explicitly says it adds capacity, uses, or another distinct benefit.
This protects the table from accidental optimization loops. It also gives a GM a clear answer: do not decide that a duplicate stacks because the fiction sounds plausible. Find the source text, then follow its exception if one exists.
Black Chrome adds variants, not a new universal rule
Black Chrome includes expanded cyberware and alternative foundations. Those entries can have their own capacity, visibility, installed component, or compatibility language. A cheaper or unusual version of a familiar implant is not automatically interchangeable with the Core Rulebook version.
For example, an alternative foundation can provide different capacity or carry a built-in condition; an integrated upgrade can affect a component nested inside another foundation. Read the individual entry from start to finish before moving capacity around on a character sheet.
Cyberware Enhancements is a separate layer, not extra Option Slot capacity. Only one Enhancement can be installed in a piece of implanted cyberware at a time, and Enhancements cannot be installed in cyberware attached to an external device such as Smart Glasses or a Battleglove. Check both limits when an expanded item and an Enhancement are part of the same build.
The Gear Guide explains how to use the Night Market Index to find the correct source and whether an expanded item is actually available in the campaign. Keep that access question separate from the slot question: an item can fit the build and still be unavailable today.
A slot check before you visit the clinic
Use this checklist when the crew wants new chrome:
- Write the item's exact category and source.
- Write the required foundation and remaining compatible capacity.
- Mark every slot the item consumes, including each half of a paired choice.
- Check whether a duplicate stacks or adds nothing.
- Check the installation setting (Mall, Clinic, or Hospital). You cannot install cyberware while suffering a related Critical Injury.
- Revisit Humanity, price, access, and downtime with the Humanity Loss guide.
That is enough paperwork to prevent most build errors without recreating the book's full cyberware tables in your campaign notes.
Where to go next
- Return to the Cyberware Guide for the live parent hub and source-aware installation decisions.
- Read the Humanity Loss guide before treating capacity as the only cost of a new implant.
- Use the Gear Guide and the original sourcebook to find a compatible item and confirm campaign availability.
- Visit the Cyberpunk RED Guide Hub or guide directory for every live guide.
The cyberweapons section of the Cyberware Guide covers integrated weapons and their tradeoffs without assuming every open slot should become a weapon mount.
Sources and scope
This guide summarizes the Cyberware category, prerequisite, Option Slot, pairing, stacking, installation, and capacity guidance in the Cyberpunk RED Core Rulebook, with Black Chrome used for expanded cyberware and variant-foundation context and Cyberware Enhancements used for its separate enhancement limit. It quotes foundation slot counts and selected per-item slot costs to support build planning, and does not reproduce full cyberware tables, prices, equipment catalogs, or item effects. Use the original item entry for exact capacity, compatibility, and installation rules.
