SUCC Score ("Magic Items" for Classic Traveller)
Traveller 5 has the QREBS framework for modifying items. Cepheus has MODES. I wanted to try and merge some of the groups together to make something a bit more usable at the table without being overwhelming
SUCC can be broken down into Safety, Usability, Caretaking, and Customization Ports. Each of these modifiers will add a DM to rolls pertaining to that function of a weapon. Let's look at an Assault Rifle with a SUCC of +1, +2, -2, 1. This would be a very high end rifle that makes shooting easier and accidents less frequent but upkeep on the firearm is more costly and taxing. The weapon also has room for one unique custom mod to be placed into its Customization Port.
Shooting with this weapon would give a PC an additional +2 to hit, regaining control of the weapon in case of a runaway belt or other malfunction would have a +1 DM added, but mechanic rolls or other rolls to fix the weapon would take on a -2 DM. The weapon has a heartbeat sensor bolted onto the front. It detects heartbeats in a 90 degree cone up to 30 meters.
The SUCC score can be applied to any item and players can pay to have specialists make better versions of the standard items. The SUCC modifiers should probably be kept between -3 to +3 to avoid modifier bloat. The Customization Ports are where more unique abilities can be slotted into weapons.
Safety
In situations where operating gear might be dangerous set a Target Number for something to go wrong. If the throw is equal to or greater than the TN then something dangerous happens. A task can be completed successfully and have something go wrong with equipment at the same time!
eg. A welder is being used by someone with Mechanics-3 to shut an airlock that is being boarded. It's damaged and old so the GM sets the Safety TN at 12. To weld the door they need to hit 10. So the player rolls 9 + 3 to get 12 meaning they weld the door shut and it explodes in their hand.
Maintenance
It's a machine's purpose to break. Assign a TN that is checked during stressful situations, on a throw equal to or greater than the TN something stops working. Otherwise check for maintenance every month for delicate items, every three months for standard items, and every six months for rugged items. To repair an item roll Mechanics or another appropriate skill for the item.
Items that are neglected confer a -1 penalty to any tasks until they hit a total of -5 at which point they break. Take better care of your shit.