Quote from: insubordinate polyhedral;1134050What would you recommend as a first pick, especially for OSR fans?

For OSR fans? Chainmail because it's by Gary Gygax and has direct lineage to OD&D and AD&D.

But most any turn-based online computer wargame will use terrain. I'm sure some good free ones exist.

Here's a website offering free rules for tabletop wargames. Plenty of fantasy ones too.
https://freewargamesrules.fandom.com/wiki/Freewargamesrules_Wiki

That's a good insight. I think I've said before that early editions of D&D assumed players were coming from a wargaming background. As the appeal widened, this became less true, which is why we got all the formalised nonsense and the rules expanded to a zillion pages - the players and DM didn't have that base of experience to draw on.

The thrill comes from meaningful decisions. The reason this seems lost to those without wargaming experience is because they expect the meaningful decisions to come from their character sheet buttons instead of the shared imagined world.

For an extreme reductive example exploded into its manifold components: a simple large tree provides several meaningful decisions in a fight. It can be A) used for cover as either i) range cover, or ii) melee cover, and either a) back cover, or b) front cover... or B) climbed for i) concealment, ii) maintained range, iii) increased line of sight/range. And once used for cover, context then further leads meaningful decisions on A) how to break cover i) left, ii) right, or iii) straight back for extra distance. Or if used for climbing advantage you now have meaningful decisions -- because you are now restricted in lateral movement (unless you choose the falling consequences) -- i) up to a) large branches, or b) less sturdy trunk top, or ii) around a) clockwise, b) counter-clockwise, or iii) back down. And so on and so forth until all party's resolve their posture (attack, talk/appeasement, hide, retreat, surrender, death, etc.) to satisfaction. It is an involved process... if you want it to be.

Nearly all rpgs recognize cover, concealment, range, movement rate, and line of sight to some degree. And this is one tree suddenly exploding meaningful decisions into several branching choices that matter. It is painfully obvious to wargamers (or people who played tag outside) what terrain adds to Meaningful Choices, yet if no one calls it to your attention it can be easily overlooked. That I feel is Kyle's point: to remind new players that the richness of the game is already in the imagination's context, not solely residing in the character sheet's buttons.

That would be one hell of a Lion & Dragon adventure!