Transcript, Feb 3 - How to Run Illusions in a Dungeon (Without Gotchas)

Original Video: https://youtu.be/6ijRtEpQknk

The transcript is lightly edited from an auto-generated one. Expect typos and worse ;)

A viewer asked, how do you handle illusions in a dungeon, like a false wall or a false floor? And actually, I love that question because illusions can be brilliant, or they can turn your dungeon into a paranoid trap. Every stone slog where nobody trusts anything. So I'm going to give you how I run illusions in old school play. 

Scary. Useful. Most importantly, fair. Because the moment your players feel like the DM can just lie, whenever you don't have tension anymore, you've got distrust. 

So we got the question then. Like what is an illusion when illusion is not a gotcha? It's a problem of perception. So I'm always thinking three things when it comes to illusions. Is there something that feels off if the players pay attention? Can they test it in a way that makes sense in the world? The game world? And if they don't test it, is the consequence fair? Something that would follow naturally. If the only answer is you should have guessed. That's not clever. That's me being smug. 

And I can be smug, but that's not what we want. People generally say illusion and mean different things. And these are the big ones. First, a sensory illusion is something that isn't physically there. 

So it's like a wall that looks solid, but you can walk right through it. It doesn't block you with stone. It blocks you because you believe it does. 

Second, a real hazard that's disguised like a pit that's absolutely real. But it's covered by an illusion that looks like normal floor. See, that's a real threat. Wearing a fake face. 

And then you have the third type. Misdirection, fake exits, fake doors, Phantom treasure stuff meant to burn off time. Split the party or put you into a bad position. Once you know which one it is, making a ruling gets relatively simple. Now do I telegraph them? 

All right, so I don't announce. There's an illusion here. And hold up a sign. No, but I do give players something they can notice. 

Now, my favorite clues are practical, physical, and generally tied to how dungeons work. So dust behaves wrong. Or that part of the floor is just too clean, too undisturbed, or there's dust piled oddly along the edge of a wall. Aaron, smoke. Behave wrong. A draught from a sealed corridor. Torch. Smoke pulling sideways. Sound behaves wrong. Uh. Short hall that echoes like it's much deeper than it appears. Monster behavior can often give it away. Goblins vanishing in a dead end. Voices behind a solid wall. Patrol routes that don't make sense. And that last one. That last one is DM gold. Okay, because it makes the dungeon feel lived in. Like a place with routines. Not a trick box. 

So in old school play the player's best tools aren't skill checks. I know I say that a lot. Or a variation of that a lot. This is aimed at my 5e players. I know I have a 5e audience. I'm just going to remind you old school play the players best tools aren’t skill checks. It's time. Caution, interaction and gear. So when someone says, I checked the wall, I ask, how are you checking it? Because the how is the entire game. 

Here are the tests that matter most, especially when it comes to illusions. 

Touch and pressure. Right? If it's a walk through illusion, this should reveal it quickly, right? You press, you lean, you push. You touch the wall with your ten foot pole. You poke it with your sword. The wall's not there. You probe ahead. Okay. The ten foot pole earns its keep. 

If they probe a suspicious floor and it goes through the floor, they should get information before someone commits their weight to that location. Throw something. Toss a pebble, a coin, a torch, especially for false floors. The sound tells you plenty. The missing coin will tell you plenty. Dust. chalk, flour. A little puff of flour at a wool can tell you if air is moving through it, especially if the flour goes right through it. Um, attempting to mark a wall with chalk. There's no wall, there's no surface. You're not marking it. But this play is smart, it's simple. And essentially it feels earned. 

Mapping and logic. If the group maps carefully, illusions will get caught constantly. That's good. That's not a bad thing. That's what careful play buys you. And just to say it, if the players interact in a concrete way, I don't make them roll to earn reality. They did the test. They get the result. 

So Okay then. Well, when do you use saves or checks or when do you roll? I use saves when the illusion is acting like an attack on the mind. Panic images, phantom threats, disorientation, that sort of thing. But the player says I toss a copper on that suspicious tile. I'm not asking for a roll to see if they notice that the coin falls through the floor. The interaction is the answer. Player action first. Only when the magic is pushing back. Now illusions should have teeth, but the bite has to make sense. 

So what consequences are appropriate? Waste of time. Right. Or counter checks. Torch burning down. Bad positioning. Splitting the party up. Noise that wakes the place up the resource drain. Because you chose the wrong approach. 

And then there are some bad consequences or inappropriate instant death with no warning and no counterplay. I'm against that. When it comes to illusions or anything else, I don't like it. I'm not a fan of save or die out of the blue. What about there? There were no clues. But you should have known. And I think many of us have experienced that crap. If a party sprints down a dungeon hallway like it's a hotel corridor. I'm not advising that you run through the hotel corridor. Is that a convention? But if you do so, yeah, you might drop through a pit there because you're not looking for it. And that's fair play. But I still want something a cautious group could have noticed. 

So let me give you two examples. The way I would run it. False wall that you can walk through. I describe a normal wall, but I usually include one clue a draft torch, smoke that's pulling strangely muffled voices, footprints that don't add up, or monsters disappearing into a dead end if they test it, touch reveals it. If they don't, they miss an advantage, a shortcut, a stash, a safer route, a prisoner, something meaningful but not campaign ending and not session fashion ending. 

What about the popular false floor over a real pit. Same deal. Normal floor. Plus one detail that nags. To clean or the dust is undisturbed. Or there's a faint hollow note to the room. Stones are a little too perfect. Or there's a slight slope. Probe it. Toss something. Test it. Now they know. Ignore it and someone drops, takes damage, makes noise. And now the dungeon is awake. That's not mean. That's not arbitrary. Just cause and effect. 

Now, the biggest illusion mistake is using illusions as a substitute for dungeon design. If the content is just a trick, players learn the wrong reason. Distrust everything. Slow down forever. The best illusions exist for a reason. Guarding something important. Supporting a faction that uses the illusion tactically. Hiding a bypass or escape route or funneling intruders into a bad approach. See when it serves the place players respect it even when it bites them. If you can answer these questions, your illusion is solid. What's the subtle clue? What's the practical test? What's the fair consequence if they ignore it? And listen, that's the whole philosophy. 

Now, if you've got a favorite illusion, one that felt fair or one that felt like a cheap shot, drop it in the comments. I want to hear your war stories. Thank you for spending your time at the tavern and God bless.