What Critical Role’s New DM Can Learn From Dimension 20

Critical Role’s fourth campaign has kicked off with a bang, shaking up the usual formula by splitting a massive 13-person cast into three separate groups, each weaving their own threads through a shared world. The most striking change, though, is the arrival of Brennan Lee Mulligan as the new Dungeon Master, stepping in for the long-standing Matthew Mercer. Mulligan, who’s made a name for himself running Dimension 20, brings a different flavour to the table. While the scale of this campaign is bigger than anything he’s tackled before, his influence is already clear, and it’s set to grow as the story unfolds. His knack for comedy, focus on genre, and willingness to bend the rules are already shifting the tone, and that’s only going to become more obvious as things progress.

As someone who’s clocked up more hours watching Dungeons & Dragons actual play than I’d care to admit, I first got hooked on the second campaign of Critical Role. After finishing that, I went back to the first, then gave the third a go. It wasn’t until I’d spent hundreds of hours with Mercer and the crew that I decided to check out Dimension 20, and I was instantly drawn in. I’d thought I was after deep dives into character, sweeping romances, and slow-burn discovery, but a few episodes of D20 made me realise I’d been missing something sharper and funnier. I’ve since watched every series, but coming back to Critical Role for this new campaign, I’m reminded why I loved it in the first place – the long-form storytelling lets you really get to know the characters. Still, I reckon there’s plenty CR could pick up from its new DM, even if it means shaking things up a bit.

Shifting the Storytelling Approach

Before campaign 4 began, Mercer pointed out that having multiple storylines lets them explore fantasy in a

"much more realistic way."

That’s already obvious with the new cast, but the rotating 13-player setup does more than just change who’s sitting where. Earlier campaigns often put the weight of the story on a handful of characters, with some players naturally getting more of the spotlight. Dimension 20, on the other hand, spreads the focus much more evenly. Even when one player’s in the hot seat, Mulligan makes sure everyone gets a fair go in the action.

Strip away the professional actors and slick production, and D&D is really just a big rulebook – one Mercer tends to follow pretty closely. That’s part of why campaign 3 didn’t quite land for me; the stakes felt high, but the risk was low. In a world where any character can be brought back with the right spell, it’s hard to feel like anything’s truly on the line. While Critical Role sticks to classic high fantasy, Dimension 20 jumps between genres, and Mulligan tweaks the rules to fit the story. Sometimes he gives players a way out, sometimes he’s out to get them. The first big moment in campaign 4 is a character death, but no one even mentions the resurrection spell Revivify. The new world’s twist is that the gods are gone, and in D&D, it’s the gods who decide if someone comes back. Mulligan sets the tone straight away – danger is real and immediate. He hasn’t spelled out exactly how death and revival will work, but the cast have talked about having backup characters ready. There’s a hint that death might not be the end, but how much wiggle room there’ll be is still up in the air.

Adapting to a New Style of Play

If you’ve ever thought about giving tabletop gaming a crack, the latest D&D starter set is probably the best it’s ever been. In Mercer’s campaigns, you’ll find hours spent on date nights, magical mansions, and shopping for fancy outfits. Some players love digging into every detail of their character, and Mercer’s all about making sure everyone’s having a good time. Over in Dimension 20, Mulligan’s games are packed with laughs, but they’re driven by genre more than character. Money only matters if it’s part of the story; backstories come out through action, not long chats; relationships are set up quickly and efficiently. Mulligan’s comedy chops have given him a sharp sense of pacing, but the shorter seasons and genre focus mean there’s less time for meandering.

With campaign 4 running longer and juggling 13 players, keeping things moving will be key. That’s already starting to show, and over the course of hundreds of episodes, it’ll only become more important. Both Mercer and Mulligan are top-notch Dungeon Masters and storytellers who’ve done heaps to shape the D&D scene. They’ve got different tricks up their sleeves and bring their own style to the table, but both are brilliant at making their worlds feel alive. In another field, this could’ve sparked a rivalry, but by bringing Mulligan on board, Mercer’s letting him build on what’s already there. We’ll see in a few years how it all plays out, but I reckon Mercer will be taking notes along the way. Who knows – maybe next year we’ll see a short, sharp D20 series with Mercer at the helm?