Modifying Weapons

Each accessory in this section is classified as an “accessory” or a “modification.” An accessory can be installed with little difficulty by pretty much anyone onto the top, bottom, or side slots. Just buy it, snap it on one of your available mounts, and you’re off and running. Note, though, that these accessories cannot be snapped on and off in a short amount of time (unless you have a slide mount, p. 52, R&G). Assume swapping them on and off takes at least five minutes while sitting still, making it impractical to do while in the middle of a firefight.

In case it needs to be said, you can’t install the same modification or accessory twice and expect to double the benefits. If you really want to, you can install the same modification in two different spots, but you’ll only get the benefit once, so you’ll be wasting a slot. You also can only have one modification per slot. Some types of weapons have further limitations—for example, light pistols can only take top and barrel-mounted accessories, while hold-outs can’t take accessories at all.

If you add an accessory to the stock, barrel, or internal slots, or add a modification, a little more work is needed. Here’s what to do.

1) Make sure you know what to do.
Make a [Type of Weapon Knowledge skill] + Logic (4) [Mental] Test to see if you know how to make the necessary modification. If you want a little help on the test, you can search for plans that might provide guidance. This can be a Matrix Search (Computer + Intuition [Data Processing]) with a threshold based on the availability of the modification (see Matrix Search, p. 241, CRB). Restricted mods should have a threshold of at least 3, and forbidden items should have a threshold of at least 6. Players can also ask their contacts for plans; use the basic legwork rules (p. 387, CRB) to discover if the contact knows what to do and is willing to share it with the player’s character. If you are able to find plans, add 6 dice to your test to see if you know how to make the modification.

2) Prepare the proper tools.
Unless otherwise noted, a kit is sufficient to attach accessories to the top, underneath, or side slots, while a shop is needed for internal, barrel, or stock modifications.

3) Roll the test.
For weapons modifications, this is generally going to be an Armorer + Logic [Mental] Extended Test, with thresholds and intervals determined using the guidelines on p. 48, SR5.