What are the limitations of them?Is there anything that's been able to actually penetrate them? Are they sourced from his suit? How much damage can he take and what types of damage?

Bumping this. Hoping someone can give me an answer.

His suit gives him a good degree of protection and healing. He rarely uses his shields in modern comics.

Do you happen to know of any time that he specifically NEEDED to use them?

You know, I'm not so sure the current incantation has them. The original Starlord had a different suit (along with his Elemeny Gun and Ship), but when they brought him out of oblivion they told the story of him versus the Fallen One. After that, Ship and his weapons were destroyed, he had to get implants and was imprisoned. He got a new suit for his current adventures.

It's been a few years since I've read the new GotG series, but I can't think of him using shields off the top of my head.

Yeah, not the new version of him. I'm talkin about pre-Fallen One battle. I can't find any instance of him using them but everywhere I read, it says that he has them so I'm confused. He didn't even use them against Thanos from what I remember.

There are only a few older issues I haven't read, like the Marvel Spotlight and Marvel Premiere issues. The Marvel Preview issues I have read I don't really recall the shields either.

Yeah. All information sites don't give any details of his shields. It's always been something I've wondered. Hopefully someone more knowledgeable on GotG and Starlord can help out. lol