I'm going to tell you about a session that went wrong.

Three hours in, the players were investigating a haunted manor. The tension was good. The mystery was landing. Then I described something I thought was just atmospheric horror: injuries on a body and environmental details to set the scene. A player went quite. The energy at the table shifted. Someone made a joke to cut the tension. The scene collapsed, and the rest of the session limped to an awkward finish.

I found out later what happened. The description hit close to something personal for that player. They didn't know it would, but they never encountered it in a game before. And in the moment, stopping everything to say "hey, this is bother me" felt impossible.

These situations are preventable. Not with mind-reading, but with better systems.

Safety tools in TTRPGs aren't about censorship or walking on eggshells. They're about building the kind of trust that lets players actually take risks. And if you're focused on creating a flow state in your games, they're not optional. They're part of the game.

Because here's the thing: you can't immerse if part of you is on guard, watching for threats, ready to protect yourself. Safety tools remove that vigilance and make immersion possible.

Why "Just Speak Up" Doesn't Work

The obvious response is: if something bothers you, say something.

But think about what you're asking someone to do in that moment.

First, they have to recognize they're uncomfortable. This isn't always obvious when you're mid-scene with your adrenaline up and trying to stay engaged with the story. Then they have to interrupt the flow of play, make themselves visible as "the sensitive one," articulate why something bothers them (which often means reliving it), and risk been seen as difficult or dramatic.

That's a massive ask. And it places the entire burden on the person who's already uncomfortable.

Most people won't take that risk. They'll sit with the discomfort, disengage slightly, and hope it passes. The session continues, but they're not all the way present anymore. You've lost them, and you might not even know it.

What I Use: Lines and Veils

Lines and Veils is a framework that comes from Ron Edwards' 2003 book Sex & Sorcery. It's elegantly simple, and I use it at every table.

Lines are hard boundaries. If something is a Line, we don't go there. It doesn't happen in our story. Full stop.

Veils are content that can exist in the story but happens off-screen. We acknowledge it occurred, but we don't describe it in detail. Think of a movie that cuts away from a violent scene. We know what happened, be we didn't watch it.

The power of this framework is that it acknowledges discomfort exists on a spectrum. Not everything is binary. Somethings are "absolutely not," some things are "yes but not in detail," and the space between those two matters.

How I Use This At My Table

I introduce Lines and Veils in Session Zero, before we've built characters or started the story. Here's my process.

I share mine first. I model vulnerability. I tell the table: harm to children is a Line for me, we're not depicting that. Detailed descriptions of certain kinds of violence are a Veil. I'll narrate the outcomes, but I won't describe the act in graphic detail.

This does two things: it normalizes the practice, and it shows that everyone, including me, has boundaries.

I offer multiple ways to share. Some people are comfortable saying their Lines and Veils out loud. Some aren't. I create a document and allow everyone to write their Lines and Veil anonymously.

I don't require people to share all their boundaries up front, either. Some you don't know until you encounter them. So I make it clear: this is a living document. You can update your Lines and Veil anytime, no explanation needed.

I don't ask why. This is crucial. When someone says "this is a Line for me," it's none of my business to ask why. We move on. Their boundary is complete information.

What This Looks Like in Practice

Let me give you a real example from a campaign I ran last year.

We were playing a mystery investigation. The party discovered a crime scene, and I started describing it. Midway through, a player typed "X" in the chat.

I stopped immediately. "You take in the scene," I continued. "And notice [specific clue relevant to the mystery]. What do you do next?"

That's it. I didn't describe the body further. I didn't ask what bothered them. I gave them the information they needed to continue the investigation and moved on.

The session continued with no disruption to flow. Later, that player messaged me privately and thanked me for how everyone handled the situation.

That's the goal. Safety tools become invisible. No spotlight. No awkwardness. No derailment.

X/N/O Cards: Real-Time Adjustment

Lines and Veils handle what you can establish before play. But you can't predict everything. That's where X/N/O Cards come in.

This system was developed by John Stavropoulos in 2001, and I've added to it slightly. Here's how it works:

X-Card: Remove this content from the story. Tap the card (or type "X" in chat for online play), and we immediately pivot away. No questions asked and no explanation required.

N-Card: "Not Now." This content might be fine generally, but right now (because of mood, energy, or timing) it's not working. We pause, skip, or come back to it later.

O-Card: "More of this." This is positive feedback. Signals that you're enjoying this content and want to lean into it.

Setting This Up

For online play, I use an extension of Foundry VTT that gives these options within the platform for players to use anonymously.

At the start of every campaign, I explain how it works and we practice using it. This is important. I'll say something like: "I'm about to describe crossing a really tall, rickety bridge. If anyone has a fear of heights, you can tap the X-Card."

This practice run does two things: it shows everyone the mechanic works, and it normalized using the card before the stakes are high.

Why the O-Card Matters

Most safety tool frameworks focus on stopping bad content. We use the O-Card because I wanted a way to signal good content too.

As a GM, I'm constantly calibrating. Is this landing? Is the pacing right? Are they engaged or just being polite? The O-Card gives me clear feedback. When someone taps it during a dramatic character moment or a particularly creepy horror scene, I know that I can keep going and give the scene room to breathe.

The O-Card in Action

I ran a session where two characters were having an emotionally heavy conversation about a choice one of them made. It was going on for ten to fifteen minutes of mostly two people talking. I wasn't sure if the table was with it or waiting for it to end.

Then someone quietly tapped the O-Card.

I let the scene as is. I didn't rush it. I gave it the space it deserved. After the session, three different players mentioned that scene as the highlight of the night.

Without the O-Card, I might have moved on too quickly. The signal let me trust what was happening.

What About Creativity?

If you're constantly worried about boundaries, won't that restrict the story?

No. The opposite happens.

When players trust that boundaries will be respected, they take bigger risks. They lean into darker themes because they know they can tap out if needed. They explore complicated moral territory because the safety net exists.

Without that trust, they self-censor. They play it safe. They hold their character at arm's length because they're not sure what's coming.

Safety tools don't limit creativity, they make boldness possible.

Here's a concept example: I ran a horror campaign where we established Lines and Veils and X-Cards on Day 1. That campaign went to places most tables wouldn't touch: body horror, existential dread, loss of agency, and deeply uncomfortable moral choices.

Why? Because everyone knew they could stop it if it went too far. That permission to tap out meant they were willing to go further before tapping out. The boundaries created the space for exploration.

What About Players Who "Abuse" It?

What if they use the X-Card too frivolously? What if they X-Card content just because they don't like it, not because it's actually harmful?

I've rarely seen this happen. Generally, players under-use the tool rather than overuse it.

But if it happens, I think it's more of a table-fit problem. If someone is deliberately disrupting the game, then that table might not be for them. The tool isn't the issue, the behavior is.

For GMs

Start with one thing: Lines and Veils in your next Session Zero.

Before you build characters, before you establish the plot, ask: "Does anyone have content they'd prefer we don't include in our game, or content they're okay with but prefer off-screen?" Offer multiple ways to share. Write them down. Honor them.

Then, when you're in play and you notice something crossing a boundary, adjust immediately. Don't wait for someone to object. If you see someone go quiet or uncomfortable, check in after the session.

Over time, add the X-Card. Make it normal. Practice using it. Show that it works and that using it won't derail the game or put anyone in the spotlight.

These tools won't fix every problem. They won't prevent every uncomfortable moment. But they'll build trust. And trust is what makes everything else possible.

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Want to play at a table where safety is built in? Check out my open games at StartPlaying. Every session uses these tools as standard practice. No manual required, and your boundaries always respected.

Photo by Alex Tan