I need to give honourable mentions to the Buffy the Vampire Slayer and ShadowRun campaigns that were the first I played in, because they had sufficient impact on me to keep me playing. However, both were long enough ago that, while I remember scenes and snippets (for ShadowRun, particularly inside the Renraku Archology, that I'd love to revisit and actually explore one day - we mostly focused on hiding and staying alive, so I didn't learn any of the secrets), I can't bring to mind any one session that would be sufficiently impactful to discuss here (well, maybe that episode of Buffy where a badly worded spell turned all me (and all the female npcs) into boys ("Make all girls like me" said the lonely boy)).
If you've been reading for a while, you'll know I'm very fond of Svetlana, my main Pathfinder character, and I worry about her future and love her relationship with King Noleski and when she died and found peace in her deity's realm, then was brought back to life and realised one day she would lose Noleski - and not even care she had - that really scared her and I loved it! (Even if no one in the rest of the party did anything. Sigh.)
And there have been some really intense moments in both Aberrant and Exalted. Anything where Bells and I get to have deep character interaction with each other or the NPCs (must be exhausting for the GM...)
I think the most impactful session would be one that took place in a game I talked about back in 2015, for the longest session I'd played in. This was the Final Fantasy Nori homebreew game my housemate, Sith, created and ran for his girlfriend Penny and our friends Owen & Rowan, and there was some real emotional intensity in the game. I'm thinking of a particular scene nearish the end, as we decided to approach Mount Gagazet and I got a load of visions trying to put me off - my parents crying and begging for help, and then my younger sister. She was called Elin and was sporty and fit, but I didn't think much of it until my GM invoked her in that scene - and played her so close to my really world younger sister, Erin (a fitness fanatic and all round amazing person) that I was in real world floods of tears and it was amazing. When he met her for the first time a few weeks later, he did freak out a little, as he saw why he'd managed to get such a response from me!
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