Next she rolls 2d6 on the encounter table she wrote for this floor of the dungeon when she designed it. She obtains a result of 7: 2d6 goblins. Another die roll tells her there are 5 of the creatures, and a roll on the reaction table gives a result of 11: Murderous. In a previous session the party has had dealings with goblins in the dungeon that have gone badly, and a small group has begun to actively hunt them through the dungeon. Steph decides that this is that group.
After generating the encounter she checks for the distance of the encounter, rolling 2d6 and multiplying it by 10 to determine that the goblins are 90 feet away when the players encounter them. Her map shows that the passage turns ahead of the party, and so she decides that they will hear the goblins coming from around the corner.
This whole process takes a couple of seconds, occurring while the players chat and joke amongst themselves. Then Steph describes the situation, and the players react:
Steph: The corridor extends about 40 feet ahead of you, with no doors or openings off it, before turning to the left just on the edge of your lantern light. You can see that there's a metal grate in the ceiling maybe ten feet ahead of you. As you look around you realise that you can hear something from around the corner - the scrape of metal on stone, the tread of booted feet, and low voices talking amongst themselves. What do you do?
Mikey (playing Tommy Twelve Teeth): Can we make out what they're saying?
Steph: If you could speak the language you probably could, but you can't. You immediately recognise this as goblin.
Mol (playing Contessa): Oh crap, do you think these are the ones that have been looking for us?
Mikey: I bet they are. Tommy is going to turn to the group and say, really quietly, "Okay everybody keep quiet, our not-so-friendly-friends are up around that corner. Maybe we can get the drop on them." Steph, does it sound like they've heard us?
Steph: Hard to tell but you don't think so yet. That said, it sounds like they're getting closer and it probably won't be long before they see the light from your lantern.
Nick (playing Arrigo): Okay, Contessa should drop back a bit with the lantern just to keep the light away from that corner. I'm going to have a quick look at that grate in the ceiling. Does it look like it leads anywhere or like I can get it open?
Steph checks her map and sees that the grate opens into a corridor on the floor above this one. She decides to make another wandering encounter check to see if it's occupied, rolling 1d6 and getting a result of 5 - no encounter.
Steph: You can see that it opens into another space but the bars of the grate are too close together to get your head through to make out any details. Now you're close you can see hinges - it looks like it could be pushed up into whatever space is above you, but it's going to be heavy. Mikey, Tommy can hear those boots getting closer. You think they're going to be around the corner pretty soon.
Steph isn't tracking the movement of the goblins here, she's just going with her gut and trying to put pressure on the group to make a decision quickly.
Mol: Okay, let's get that grate open and climb up out of this corridor. I've got my lantern. Maybe I could drop it on them when they move beneath us. Would a lantern explode?
Steph: I love that. There aren't actually any rules for using lanterns as weapons but how does this sound? Since you're just dropping it from above the group as they move beneath you you probably don't need to roll an attack, you can just do it. All weapons in the game do 1d6 damage, so we'll deal that initially and I'll roll to see how many enemies it actually hits. Then we'll use the normal light rules to see how long the oil continues to burn for, and anybody in the space where the flames are takes damage every Round they're there. Sound good?
Steph: Brilliant. Okay, Arrigo, talk to me about this grate. You can hear the boots now and it looks like this thing is going to be heavy. What are you doing?
Nick: The ceiling is ten feet above me, right?
Steph: It is, yeah.
Nick: Okay. Mikey, get Tommy over here to boost me up and then I'm going to try and get this grate open.
Mikey: Got it, let's go.
Steph: Okay, I'm not going to ask for any checks for Tommy to boost Arrigo up because that's pretty straightforward. Arrigo, we'll make a Brawn check to get this thing open quickly. It's heavy but it's not locked so you can definitely open it, it's just a matter of time here - will the goblins get around the corner while you're struggling with it, or do you open it in time for everyone to climb up through the hole. Sound good?
Nick: Sounds great. What am I doing, making a Brawn check?
Steph: Exactly that.
Nick rolls 1d20, getting an 18. Arrigo's Brawn is 15, so this is a failure, but initially Nick doesn't realise it.
Nick: Yes! 18. Smashed it.
Steph: Oh wow is your Brawn 18? That's high, I never realised!
Mol: You have to roll under, not over, remember?
Nick: Oh damn I always forget that!
Steph: Okay, so the goblins come round the corner while you're straining with the grate and they see you. You hear the rattle of swords being drawn and a snarl of many voices as they-
Nick: Wait, shit, sorry, sorry to interrupt. Can I exert myself on this?
Steph: Oh yeah of course you can, sorry! You rolled an 18, right?
Nick: Yeah it is, and my Brawn is 15 so that's a difference of 3. So I subtract 3 points from my Brawn and then it's a success?
Steph: Yep! So let's roll it back a bit. The goblins haven't come round the corner yet. Arrigo pushes and strains against the grate and it won't move, but they bear down and grind through it and manage to lever it up enough to pull themselves up and through the gap. Your Brawn is reduced to 12, and if you want to recover it you'll have to take a week of bed rest once you're back in town and roll to see how much of your strength you get back.
Nick: Can I make sure that I lower it quietly once I'm up there? I don't want to give the game away.
Steph: Absolutely. And then I assume Arrigo reaches down to help Tommy and Contessa up, right?
Nick: That's the plan.
Steph: Fantastic. So you pull yourselves up, Contessa's boots just clearing the opening in the ceiling as you hear the goblins round the corner and start moving down the corridor towards you. Contessa, you wanted to use your lantern to drop down on them - that means you're keeping it lit. Are you doing anything to shield the light from spilling through that hole you just climbed through or are you happy for the goblins to see light up there?
From here play continues, with the group triggering their ambush and play moving into a brief combat phase. Because of their smart thinking and higher ground the party overcomes the goblins, eliminating a persistent threat that's been plaguing them over several weeks of play.