Yeah, I had a lot of fun with (basic) D&D;.
I once created a super massive dungeon, worked out on large sheets of grid-paper in great detail. One layer was entirely taken up by a massive underground lake with a few small islands (and a few large monsters), while another was completely populated by thousands of Orcs. Being their ‘home villiage’ and full of their wives and children they were none too keen to start anything and would just glare at the party and pointedly polish their weapons (or is that polish their pointy weapons?). Keep your head down and your mouth shut and don’t wander into any dead ends and you’d suffer nothing worse than a few snarled insults and a bit of jostling.
Of course, the party I DM’d through that level happened to have a CG Paladin on their team. After I pointed out that either his player makes him act to his alignment or I’ll start penalising him, things got very interesting. He’d constantly try to dash headlong into the melee with sword drawn, shouting foul oaths, and the more lawful/neutral members would repeatedly restrain him by whatever means they could. At one point this involved dragging him by his feet (his hand’s were bound) through an orc farmers’ market (plenty of cattle) with whatever bits of clothing they could spare stuffed in his gob (“John, roll a saving throw against poisoning from Lundi’s socks!”). Okay, so I added the market on the spur-of-the moment for laughs.
A game that you could make up as you went along lent itself to certain abuses, but with a bit of forethought and an eye to giving the players a good game, it was never less than fun. It might seem like a frivolous waste of time to some, but I always found that the best GMs were good player managers, they kept the team creative and heading in the right direction.
Of course, there were bad GMs too. I remember one game of Traveller were we spent a lot of time training and learning about a particular world we were going to ‘mercenary’ on, arrived there and surrendered our weapons (as we expected to), then walked out of the space-port gate straight into an ambush by goons with plasma weapons.
The GM’s answer was “Why didn’t you smuggle your guns and armour past security?” Because space-port security on a world with strict policies on use of weapons would likely be very tough and the penalties for smuggling very harsh. And how do you smuggle armour capable of withstanding sustained plasma fire through anywhere? Paint SPF 5 billion on it and claim you’re very easily sunburnt? No, we arranged for our ‘heavy art’ to come in separately (and deniably) and intended to negotiate for some illicit small arms with our on-world contact. I never saw that GM’s notes, but someone who did said that they read like a script and we were expected to try to sneak out of the spaceport, fail, and then shoot our way free. So basically Robert slagged us for thinking up our own solution instead of using his.
Ironically, he later went into management.