Let's grab something I loved from an old game...
Something that hasn't really been seen in many of the more recent games that I've been looking at (whether independently produced or mainstream).
(Yes, I'm doing this because I've noticed that my blog is running behind on it's weekly game mechanisms and some of my own ideas just haven't seemed adequate as I've started numerous times to write this post)
I love the concept of the life path in Cyberpunk 2020, I adapted some of it's ideas when I wrote the Eighth Sea. I know that the concept has also been thoroughly explored in games like Traveller and HoL (with both of these games offering options that can kill a character before they even enter play).
I like the idea of rolling a bunch of dice to fill put the backstory of a character instantly gives characters a time and place in the setting where they will be developing their stories. It helps to set the tone of the game, gets into players minds that this is a game and that random chance will play a part in the development of the stories. This said, a good system to develop a life path should use a similar type of mechanism to that which is used in the game.
If your game uses percentile dice, then develop a life path system that uses percentile dice. If your game uses cards in a manner similar to poker, then have a life path system that uses the card values, combinations and other tropes of poker.
Life path systems also give players an idea that their character's backgrounds will play a part in the narrative to follow. A friend made during the life path rolls could be jeopardised during the course of play, a family member lost during the pre-game rolls could be found during the course of the story.
These are the types of things that really help to give depth to characters more than just the numbers on the page. They help to construct an imaginative environment, and help to connect players to that environment through their characters. A good life path system isn't an excuse to avoid coming up with a solid character concept, but it should help inform the reasons for how that character concept has developed.
Based on some of the things that I've been reading lately, there are probably a few members of the roleplaying avant-garde who would claim that life path systems are a crutch for a poor imagination. But I thinks that's a load of phooey.
(I'm surprised that the spell checker has allowed "phooey" as a legitimate word.)
One of the things that I've really noticed with the core members of the roleplaying avant-garde is that many of them have become like art critics...not really caring what the public cares about with respect to art, and becoming so caught up in their theorising and hubris that they fail to understand why the rest of the world doesn't catch on.
There's probably quite a few old mechanism gems in the pages of forgotten games (or at least games which have ceased being fashionable). I'll have to start searching through some more of them.