Hey guys! First post here, no big deal but bear with me.

I have two NPC droids on my PCs' ship - the Medical Assistant Unit, Medical, or MAUM, the medical droid that frets over them when they come home from an adventure, and Double Down, an assassin droid turned gambling droid turned murderbot that guards the ship and can fly it to them if needed. Neither is an active presence in most missions - MAUM is a good helper in getting the party over their wounds, and Double Down, while cool, doesn't come with them to fight, so his presence is more reassurance than help. I like having the NPCs not be useless, but if I advance them like I advance the party (and would advance a droid character if I ever played one), they get very good at their assigned roles with the XP the party goes out and earns.

Should I tone down the NPCs' leveling so they don't keep up? Should my NPCs level at all? Any advice would be appreciated!

I wouldn't give them XP at all. It sounds like you've taken steps to prevent them overshadowing the PCs, but that could change if they get better. Better to have the PCs outgrow the need for them, I think.

My astromech has been around since the start of the game and while he's not getting experience at the rate the rest of us are, he's higher than stock Astromech stats. You don't have to bump them a lot, but just a little bit here and there to show that they're developing too.

It's probably more important to flesh NPCs out as real live people than generating a stat block for them. The stats you can hand wave as necessary.

I mostly agree with the arctic avians. However, if the PCs do want to upgrade the droids, they could take an adventure to search around for just the right hardware upgrades an protocol upgrades. throw in some stingy and outlandish junkers and you could have a fun session.

Wait, Orange is a Penguin too? Hmmm. . . .

Subtitle, Penguin A pushing Penguin B into a puddle

I don't think there is an up or down option here. If someone doesn't mind running two characters and will actually play one of the droids to a certain extent, and the droid tags along and contributes I'd say level them. If not, then I wouldn't. Just depends.

Wait, Orange is a Penguin too? Hmmm. . . .

Subtitle, Penguin A pushing Penguin B into a puddle

IT WAS YOU !!

If the players want the droids to upgrade, let them spend the cash to upgrade them... and like was said above, that might not be so easy (especially with an assassin droid).

If the players want the droids to upgrade, let them spend the cash to upgrade them... and like was said above, that might not be so easy (especially with an assassin droid).

Yep, that seems like a no-brainer. Let them pay to upgrade.

What if the Droids outgrow the need for the PCs.....dun dun dUUUUNN!!!

Give them traits they need. Everyonce in awhile have them hint that they need upgrades and then have the party go on an adventure to get more upgrades.

MAUM could be all "sir, repairs to your fleshy chasis if I were equipef with the new z8 medical arm. You would be subject to less sweeling in your lower extremities"