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Design & Development
by Stephen Radney-MacFarland

The Design & Development article series premiered on the D&D website back in September 2005, and has been a staple ever since. With the approach of 4th Edition, and our designers and developers focused on the new edition, this column will be the primary vehicle for 4th Edition coverage. We’ll not only give you peeks at what’s forthcoming, but also the “how” and “why.”

Keep in mind that the game is still in a state of flux, as refinements are made by our design and development staff. You’re getting a look behind the curtain at game design in progress, so enjoy, and feel free to send your comments to

Traps have been a part of the Dungeons & Dragons game since its earliest days, fiendish perils that stood right alongside monsters as primary hazards to adventurer life and limb. Some adventures, like the classic Tomb of Horrors, featured traps as the chief threat to life and appendage. Unfortunately, they've rarely had a positive effect on the game. In the early days, DMs all too often felt compelled to demonstrate their cleverness and punish players for making "wrong" choices -- even a choice as simple and random as which passage to explore. Old-school players in the hands of such a DM responded by changing their characters' approach to dungeon exploration. The "right" way to play the game was to slowly and laboriously search each 10-foot square of dungeon before you set foot on it, or to use magic that made traps completely pointless. Neither option was much fun.

By the time 3rd Edition rolled around, traps had become a much smaller part of the game, something you might run across once or twice in an adventure -- and rarely very satisfying when you did. Who wants to roll an endless series of mostly pointless Search checks? If the players decided to simply explore the dungeon and search for the "fun" and got whacked by a trap instead, they felt like they'd been sandbagged by the DM.

Consequently, we thought about simply "disappearing" traps from the game, but then we decided to take a shot at fixing them first. Making traps work right certainly offered some significant upside. Traps are a good way to showcase skills. They're a good way to introduce puzzle-solving into the occasional encounter. They're an excellent way to complicate an otherwise bland combat encounter and add a highly interesting hazard that players can exploit -- or must avoid. And sometimes it simply makes sense in the context of the story that the builders of a dungeon might have built a trap to guard something.

The first thing we did was spend more time and attention on traps as components of existing combat encounters, or as multi-component encounters in and of themselves. The Encounter Trap system described in the Eberron sourcebook Secrets of Xen'drik offered a great starting point. By treating a trap like a group of monsters with different components operating on different initiative scores, a trap became a real encounter rather than random damage. Most traps work best when they "replace" a monster in a combat encounter, or serve as a hazard equally threatening to both sides. We think that our ideal encounter consists of some of the PCs battling monsters while some PCs deal with a trap or similar hazard. Meanwhile, everyone on both sides of the battle must contend with some sort of interesting terrain element (although the advantage probably lies with the monsters there -- after all, this is their home). In this way, traps become an integral component of an encounter, rather than an afterthought or something a bored DM springs on unsuspecting PCs between fights.

The second significant change to traps in the game is changing the way we look at searching and exploring. Rather than requiring the players to announce when and where they were searching, we decided to assume that all characters are searching everything all the time. In other words, players don't need to say "I'm searching for secret doors," or "I'm searching for traps." Instead, characters have a passive Perception score that represents their Take-10 result for searching. When something hidden is in the area, the DM compares the passive Perception scores of the PCs with the DCs of the various hidden things in the area. In the case of hidden creatures, the DC is the result of their Stealth check. For things like hidden traps, hazards, or secret doors, the DC is usually static.

While Perception is usually the most important skill when it comes to sussing out a trap, it's not the only skill useful in determining the danger of traps. Based on the nature of the trap, skills such as Arcana, Dungeoneering, or even Nature can give a PC the ability to learn of the existence of a trap, figure out its workings, or even find a way to counter it.

Lastly, we wanted to expand the ways in which you could counter a trap. Much like figuring out that sometimes you wanted other skills to allow a character to recognize a trap's threat, we made an effort to design traps that could be countered with an interesting skill uses. Sometimes we're pointing out what should be obvious, such as that an Acrobatics check can be used to jump over a pit; other times we're going to expand the uses of some skills with opportunistic exceptions, like granting a skill check that gives the characters insight on how a trap acts and ascertain something about its attack pattern.

Don't fret, rogue fans. That class and other characters trained in Thievery are still the party's best hope to shut down traps quickly and well. The goal was to make traps something that could be countered when a party lacks a rogue or the rogue is down for the count, not to mention make traps more dynamic and fun. In doing this, we quickly came to the realization that canny players, in a flash of inspiration, can come up with interesting solutions to counter even the most detailed traps. Instead of trying to anticipate these flashes though design, we give you, the DM, the ability to react to player insight with a host of tools and general DCs that allow you to say "Yes, you can do that, and here's how." We think this is a better approach than shutting down good ideas from the players for interesting story and challenge resolution, simply because you lack the tools to interpret their actions. After all, you should have the ability to make the changes on the fly that reward interesting ideas and good play. This is one of the components of every Dungeons & Dragons game that allow each session to be a fun and unique experience. Traps, like all things in the game, should embrace that design philosophy.

About the Author

Born on a stormy Christmas day, in our nation’s capital, during the Nixon administration, the stars were definitely wrong when Stephen Radney-MacFarland came screaming into the world. Spending most of his impressionable years as a vagabond and ne’re-do-well, Stephen eventually settled in the Northwest to waste his life on roleplaying games.

Once that RPGA guy, Stephen is now a developer in RPG R&D where he doesn’t create the traps … he just makes them deadlier. He also teaches a class on roleplaying design for the Art Institute of Seattle, molding the minds of young and upcoming designers. Be afraid. Be very afraid.