Traps add fun to Dungeons & Dragons when players can (a) make choices that help uncover them or (b) interact with them. Interaction includes crawling to evade scything blades or stuffing the mouth of the green dragon statue to block a jet of poison gas. Fun interaction favors discovery over die rolls and certainly doesn’t include just subtracting damage from hit points.

The standard routine for traps in fifth edition skips all the entertainment. The game’s example goes like this: A character’s passive perception reveals a trap, then a player rolls a Intelligence (Investigation) check to discover how the trap works, and then someone tries a Dexterity (Thieves’ Tools) check to disable the thing. This rote mostly dodges any potential fun. Passive perception just skips any engagement, and a trap’s discovery leads to zero choices. The only activity comes from die rolls. The only decisions come during character building. I daresay the procedure’s designer dislikes traps, but dutifully includes them based on D&D tradition.

Because the fun of traps comes from finding and interacting, dungeon masters can watch players evade them all and rate the session a success. Still, characters may overlook a few gotchas. Unnoticed traps that spring on characters serve three purposes:

• To make careless and reckless choices lead to consequences.
• To set a mood of peril.
• To warn of more dangerous traps ahead.

For setting the mood and as a signal of more traps, the devices players do find work just as well. Even spent traps and their victims’ remains serve the purpose.

When players spot traps and use ingenuity to evade them, they gain the pleasure of figuring things out and feel clever. But even traps where the interaction goes wrong can prove fun. On the Mastering Dungeons podcast, Teos “Alphastream” Abadia says, “I recall an adventure that had a series of traps that were engaging enough that my party activated all of them after spotting all of them, and we were all laughing and having a great time. At one point a player found this pressure plate, and somehow, she concluded that this was the safe spot, so she jumped on it.” Later in the gauntlet, the group found a pit that dropped to a strange growth that hit the bottom, so someone dropped a torch to see. The growth was brown mold, which grows with fire.

The advice in the Dungeon Master’s Guide for running traps favors using passive Wisdom (Perception) scores to decide when characters notice traps. This advice aims to speed play by skipping time wasted looking for non-existent traps. But passive perception also loses the surprise and fun of rolling the dice. (See D&D and the Role of the Die Roll, a Love Letter.) Also, passive checks eliminate decisions that lead to uncovering traps, except for choices during character creation. Sure, no one wants a game slowed by fruitless checks for traps, but traps work best where players expect them—preferably past the spiked and burned corpses of previous explorers in dungeons with words like “horrors,” “death,” and “Tucker’s” in the name.

Passive perception can fill a role in a dungeon master’s trap game. Perception enables characters to notice things that simply require keen senses, such as a trip wire strung across a corridor. Passive perception can feel like a rule where the DM just chooses whether someone finds a trap. After all, the DMs who set DCs often know their group’s perception scores. But when only the characters at the front get close enough to spot traps, the choice of marching order factors into success. Sometimes the choice to light a torch also leads to success by eliminating the -5 penalty darkvision suffers in total darkness.

If someone observant leads and that character inevitably spots a trip wire, then the incident still sets a mood and signals more traps to come. Plus, players who chose the Observant feat feel rewarded for their choice.

Even the highest passive perception score falls short of trap radar. Totally concealed traps such as a pressure plate buried under dust require a search to uncover. For searching, choose Intelligence (Investigation) checks. Someone skilled at Investigation spots ordinary but significant details such as the residue around the gaping mouth of the dragon statue or the scratch left by the swing of scything blades. When players must ask for searches, they make the choice that a uncovers a trap. Plus, the roll for success adds the uncertainty that passive checks lack, and that roll adds surprise for the DM.