Do my items get repaired automatically, based on my Repair skill? Or is it something I need to "activate" to happen?

What if I have no Repair skill, but one of my followers does? Same question as above.

Thank you!

Magnus has a low Repair skill, which is better than my zero Repair skill. I tried as you said, and it didn't indicate Magnus stepped in (although the game could very well have used his skill anyway).

I got 3 failures in a row before getting "you lack the required components" or something like that. I'm trying to repair my armor, btw, which we could all use a little of right now (as well as our weapons).

I think Matchstickman is correct in that when you use a skill, if one of your followers is better at it than you, they will automatically step in and do it. I know that this happens with picking locks, for instance. But I'm not sure about repair; there might be an issue with the fact that you need to be holding the item to repair it, so since Magnus isn't holding it he doesn't help you?

One more suggestion is to try talking to Magnus, and see if there's a conversation option to have him repair something. I know that this is how you get him to craft things for you, so maybe you can also use his repair skill this way.

No luck talking to Magnus. I'm gonna keep an eye on his damaged weapon, though...see if it gets Repaired as time goes on. Then I'll know if he's Repairing it on his own or not.
Ah, the heck with it. I've got a high INT so I put one point into Repair. Now I'm repairing stuff like nobody's business, without a significant drop in my Magic aptitude. I'm happy enough.

Usually your companions will say something like "allow me, ma'am" if they're taking over - and you can hold Ctrl when clicking to prevent this. You could try repairing with different skill levels and see if Ctrl (or Magnus-not-in-party) repairing gets different results from doing it when he might be taking over . . . (and if he develops expert skill, then there are pretty distinct differences in the damage done by repair, so it should be clear pretty quickly)

Yeah, that's something I just finally noticed after repairing a bunch of my stuff...that repairing it damages its max HP value. Might have to go re-load a previous save. :-(

If you don't mind paying for it, the blacksmith in Tarant can fix your stuff up without damaging the max health. Other blacksmiths may also be able to do this, but I think their repair skill needs to be very high. I only occasionally saw any damage to the max health when using the smith in Tarant and it was extremely minor, like going from 100 to 99 or something.

I could deal with that. I've got somewhere around 26k gold right now (I killed an evil shopkeeper...I wanna it was in Tarant(?)...and looted him).

Does a decreased value of for example a sword, damage the hit-points it will do while striking?

Great to see so many people playing Arcanum. :-)

I'm pretty sure the stats (damage, speed, etc.) remain the same, it just means it will break more quickly next time.

If the stats are to be believed, this is indeed the case. Experience with almost-broken weapons suggests they are just as effective, although they were un-repaired (normal Max HP).

Also, if you need money, you can exploit the store chests - unlock it, then sell a high-value item repeatedly (taking it back out of the chest) until the shopkeeper runs out of cash. Walk until the shop is out of visual range, advance time one day, repeat. There's even one shop where the chest has a *key* -- one pick-pocket [worth a fate point but he's an easy mark] and you have easy infinite cash.

Edit: a correction: apparently damaged weapons have a higher change of critical failure. However, I'm not sure what happens with reduced max HP : an item that once had 100 durability and now has 50/50 might be considered half-damaged or undamaged for the failure calculation. It would take far more tests than I care to do to figure out. >.<