d100 SPECIAL system is great, first played it over a decade ago after discovering the pdf online, and knowing the original video games they're based on. I didn't write the rules, and it's a fan game, so much of the content is gutted, still one of my favorites.

The ruleset is approved of by, and dedicated to Jason Mical's Fallout PnP 2nd Edition, which are well-written, unofficial tabletop iterations of the Fallout universe where it was at 20 years ago.

Features include:

• Races,
• Traits,
• Unarmed Combat maneuvers,
• Additional Combat actions,
• Perks (experimental)
• Characters, (some pre-rolled characters too)
• NPCs, Simplified NPCs, NPC Generator, PC Generator
• Items, Item Shop Inventory Generator,
• Weapons and Armor Condition tracking (basically like HP, automatically goes down from damage or misses)
• Vehicles, 
• Combat Tracker, NPC actions and Vehicle Systems within,
• AP system
• AP using actions remove from current AP and reset on CT turn arrival
• Cover setter in the CT, manually set
• Weather, Night
• Attacks take all things into account, including range in meter hexes, outside of optimal range, AC and much more
• Optionally roll damage separate to attacks
• Weapons can store a clip of applicable ammunition or charges of power cells (and can be taken out of the weapon to storage or discharged from use)
• Modifier stack from the bottom left applies to the d100 target success rate, (unused for damage)

Here's a video going over many of these features during version 1.3

https://www.youtube.com/watch?v=yRCBx7oxS6M