Part of https://www.facebook.com/RPGaDAY/
I’ve got two different answers here.
For the first one – my first session with the group I dropped in the swamp really surprised me because they were so much more interactive than any other groups I’ve experienced before. They were talking to the NPCs, asking questions, interacting. A couple of them even acted out playing cards while trapped in a lizard-folk hut overnight (the players didn’t have any cards, they were just making up their hands on the spot!).
It surprised me because I’m just not used to the players getting so involved in driving the story forwards. But it also surprised (and pleased) me because it made me so much better at improvising having them to riff off. Such a different style of play.
The other surprise I’ve had is moving to D&D 5e.
Coming from the BECMI set, everything is so much more detailed and complicated and there are so many more options and styles and details that I just can’t keep them all in my head. Players are so much more powerful so much more quickly and I can’t keep up with all the feats and keep the monsters challenging. Even after a year I’m still under-estimating what it takes to make a seriously challenging battle, and I keep getting caught with class features I didn’t know existed.
As a recent example, I had a battle with a half-dragon who challenged (Hoard of the Dragon Queen). I allowed the characters to taunt the half-dragon into taking on both of the fighters simultaneously; these are 3rd level, a fighter and a paladin.
Both have the defence feat, so they can impose disadvantage on an attack against an ally within 5′. The fighter is also a Battle Master, so he seemed to keep saying “oh, I use this maneuver with my superiority die”. I completely wasn’t ready for them – I actually accused him of making up things on the spot at one point, and had to go and read up about the maneuvers once the session was over.
And these are just fighters. There are 12 different classes in the base rules, with 9 races. All of these have variants. And then Volo adds 8 more races, and Xanathar adds more class variants. It’s too much!
Next: How has gaming changed you?