Like the header says, I've been playing D&D and other TRPGs for 40 years and going. RPGs are my hobby of choice. My first planned date with my now-wife was a D6 Star Wars session (which I must write up some day). The default present my friends get me is a bundle consisting of a college-ruled notebook, a book of graph paper, and a pack of mechanical pencils.
My wife has been playing with me since we met, obviously. Once we began having kids we all knew it was just a matter of time. Our oldest (Jack) was inventing D&D monsters when he was 4 (and the lemon devil is feared in my campaigns to this day!). Jack was reading the AD&D PHB by 6 and asking to play soon after, but his 3 younger brothers interrupted a lot, so he and I played a lot of Starfleet Battles, instead.
Finally, it happened. Nick, the then-youngest, turned 6 and had a ton of patience. I had been working on an AD&D 2e S&P campaign (my wife's favorite RPG is 2e with all the Skills and Powers books!). The wife and kids all made characters, and we started a dedicated campaign from 1st level.
The climax, although not end, for that first party is here.In the 9 years since we have played a ton of RPGs ranging from the Battletech RPG to HERO 6e to a series of playtest sessions for Rolemaster Unified. Three of my four oldest have DM'ed at least a bit and a common lament from Nick is that we need to become independently wealthy so we have the time to play 8 hours a day 4 to 5 days a week. The oldest is running his own group with friends at a FLGS and the kids even run their own games (usually 4e or 5e) among themselves.
One thing that I have noticed is - while I know a fair amount of fellow gamers with kids who play, mine seem older. Jack is almost 21, for example.
So here are some of my observations about my own older second generation players
They Have No Idea How Good They Are
Outwitting traps, puzzles, etc. in games? Modules made by others? Sometimes they don't notice that there is a trick because it is so intuitive to them. My favorite was from the Hidden Shrine
I run a 'classic' module every Halloween weekend. Usually heavily modified.
I was running the 'inverted' version where they start outside. They get to the top.
[SPOILERS]
They see the altar to the bat god. The conversation went something like:
Jack: "Mayincatec altar; bat god. We obviously need to spill blood to open a secret door."
Sam: "Into the bat mouth. Probably has to be fresh, too."
Nick: "I bet it bites down."
Alex: "Obviously it won't let go; use the Bag of Beans."
Jack: "Certainly."
[end SPOILERS]
Here's the thing; I've never used vaguely Aztec stuff before, I think I've hit the party with 4 traps ever, and none of them had read the thing!
They do this sorta' thing all the damn time, too.
Now I just assume I have to make everything 25% more deadly and that 2 or 3 of my 3 twists won't work.
Time Sucks Don't Work
I gave up on giving them timed quests and then trying to distract them. Oh, I'll give a time limit, but I just know that no amount of 'there might be gold if you pause' works.
They're Opinionated
This may be genetic.
Nick? He's an AD&D, no Unearthed Arcana, 3d6 in order and suck it up, kinda' guy. There is no other "real" Dungeons & Dragons. He hates that I use my house rules in my 38 year old campaign and mentions it a lot.
That's just an example.
Thing is? Its wonderful. They can logically defend their opinions and aren't unwilling to try new or other things. Their strong opinions lead to, oh, Nick's many great new magic items, or Jack's wildly original campaign settings or Alex's stellar roleplaying at the table, or Sam's keen insight into design.
They Love RPGs
They love that I have for this crazy pastime? They caught it. It is something we share and that binds our family together.