I'm using Keep on the Borderlands, keeping things mechanically as-written but adding and adapting the context and plot details to add some depth and complicate the straightforward colonialism of the original.
The setup:
A lone keep sits on the edge of the Empire. Once it was a prosperous place, the nearby mines bringing in people and trade, but one day without warning foul creatures began to issue from the mines, raiding and killing across the Borderlands. Some say the monsters came from the wildlands beyond, others that they miners woke them from a magical slumber beneath the earth. Whatever the cause, the result is the same: no miner survived the initial attack, and those who settled nearby were either killed or driven off. The Keep is now the only safe haven for Lawful folk, and the ruined mines have a new name: the Caves of Chaos. A call has been put out for brave souls to defeat the monsters and make the caves safe for mining once again.
Thoughts on the system:
- when two sides roll the same for initiative it is delightful chaos.
- really enjoying rolling for monster's reaction, even when it seems obvious.
- I like how inventory and weight works: all your miscellaneous gear together had a set weight and only Armour, weapons, and treasure had to be calculated.
What's happened so far:
- the group arrived at the Caves of Chaos and wandered into an orc cave. The orcs chased them off, but the group learned they might be able to impress them by hurting the goblins to the south.
- they went into the Goblin cave and immediately ran into a patrol who alerted the guards. Half the group was killed and the rest fled.
- the survivors made their way to the Keep, restocked and met new adventurers to join their group, including an elf npc.
- they had heard a rumour of a dangerous but knowledgeable hermit living in the woods to the north, so set out to find him. He approached and threatened them during the night, but they convinced him not to kill them. He told them that if they could tell him something he didn't yet know about the caves the next time they met, he would share his knowledge, and if they told him something they already knew he'd kill them.
- they returned to the Caves to find the goblins had built a barricade in the entryway to their cave. In an attempt to smoke thegoblins out the group lit the barricade on fire and hides nearby. No goblins emerge but an ogre comes out of a nearby cave. It sees them and charges, but they manage to kill it with arrows before it gets a hit in.
- they explore the orge's cave, find his treasure, and find a connecting passage to the goblin Caves. They take a group of goblins sent to put out the fires by surprise and kill them, then manage surprise and kill a group of guards. One Goblin flees up a staircase to a closed door, and a hobgoblin on the other side sees the adventurers, but seems unconcerned.
- exploring deeper into the Goblin cave, they hear many goblins in a large chamber ahead and decide not to risk it, retreating out of the Caves with their loot.