It could be about giving characters in the Harry Potter universe a second chance at something. Maybe a character who made a big mistake gets a chance to redo a decision. For example, if Neville Longbottom had a second chance to stand up to Voldemort earlier in the story, it could change a lot of things.
Often in fanfics like 'second chances harry potter fanfic', it's about reimagining key events. For instance, the Battle of Hogwarts. What if some of the fallen characters were given a second chance to fight? It could show different strategies, new magical abilities that might have been discovered if they had another shot at it. It could also delve into the emotional side of things, like how the characters would feel about getting this second opportunity, whether they would be more confident or more afraid of failing again.
It's hard to say for sure without reading it, but it could be Harry Potter himself. Since it's a Harry Potter fanfic, he's likely to be involved. He might be the one getting a second chance at something important, like saving Sirius Black.
One interesting plotline could be a character who made a big mistake in the original series getting a second chance to rectify it. For example, a Death Eater might be given a chance to turn good and fight against Voldemort. Another could be a character like Neville having a second chance to prove his worth even more spectacularly, perhaps by being the one to finally defeat Voldemort. Or it could be about Harry having a second chance to save someone he couldn't save before, like Sirius, which would lead to a whole new set of adventures and challenges.
Obviously, Harry Potter would still be one of the main characters. Since it's about second chances, he might be dealing with things he didn't get to do right the first time. Hermione Granger would also be a key character as she's always been resourceful and could play a big role in making the most of these second chances. Ron Weasley too, as he's Harry's best friend. And perhaps some characters who were on the fringes in the original, like Luna Lovegood, could step into more prominent roles this time around.
Some fanfictions might have a plot where characters who died in the original series are brought back and given a second chance at life. For instance, Sirius Black could return and this time, he and Harry could have a proper relationship, with Sirius being able to guide Harry more effectively. There could also be a plot where the magical world as a whole is given a second chance after the destruction caused by Voldemort. New laws and systems are created to prevent such a dark wizard from rising again.
In the 'Second Chances' 'Game of Thrones' fanfic, it might focus on different plotlines. For instance, it could explore how a minor character who was overlooked in the original series gets a second chance to shine. It could be that this character has some hidden power or knowledge that, with this new chance, they can use to influence the power struggles in Westeros. This could lead to new alliances and rivalries that we didn't see in the official story.
Harry Potter himself is often a main focus. Since the title has 'Second Chances', it could be about Harry getting another opportunity to deal with his past traumas or make different choices. Hermione Granger is also commonly focused on. Maybe she gets a second chance to show her intelligence in a different way or to fix a relationship that didn't work out as well in the original story. Ron Weasley too, perhaps he has a chance to be more confident or to be a better friend in these fanfictions.
Fanfics are all over the place in terms of themes. 'A lifetime of chances fanfic' could potentially be about a character's journey through different scenarios where they are presented with one chance after another to change their fate. It might explore how they grow, learn, or make mistakes with each new opportunity.
I'm not sure specifically as I haven't read it. But generally, in Naruto fanfictions, 'Second Chances' could be about a character getting a new opportunity to change something in their life, like Naruto getting a second chance to save someone he lost, or Sasuke getting a chance to redeem his past actions.
I'm not sure specifically as I haven't read this particular fanfic in detail. But generally, in RWBY fanfics, it could involve the characters dealing with themes of redemption and new beginnings which might be related to the 'second chances' in the title.
The main characters could also be entirely new characters introduced in the fanfic. The author might create someone who has a unique connection to the events of the original series and is given the task of changing things. However, it's also possible that classic villains like Cersei could be main characters if the fanfic is about giving her a second chance at ruling, perhaps with a different approach this time.