Trap Generation and Placement

The trap generation chart below is not an exhaustive list. In fact, a quick perusal of this chart should readily produce several variations on the themes presented herein. It should also be noted that some traps can be combined to great effect. For instance, a spiked pit trap might trigger a swinging log to "help" the players in. Use your imagination.

There are various possible trap levels appropriate for different situations, as follows:

Nuisance: A hidden trap door with a 10-ft drop.

Hazardous: A hidden trap door with a 10-ft drop onto spikes.

Dangerous: A hidden trap door with a 10-ft drop onto poisoned spikes (for extra nastiness, have the pit lock shut after the victim falls in).

Fatal: All the above plus a 10 ton stone block the exact shape of the pit that drops down from the ceiling into the pit.

Trap Placement

Generally traps should be suited to the dungeon level on which they are situated and the potential treasure they guard. Thus a trap on the first dungeon level that leads to an area infested with ferocious but poverty-stricken monsters should be nuisance, while a trap on the sixteenth dungeon level that protects a pair of dragons' treasure hoard while the dragons are out hunting should be fatal.

Intelligent creatures that live near a trap will always have some means of avoiding or disarming it—whether this be an alternative route they habitually take or some mechanical or magical means of bypassing it. If they use the trap to protect their lair, treasure or young, they will maintain the trap to the best of their ability (perhaps cleaning away bloodstains or other evidence of its existence, for example). And if the player characters learn to bypass the trap, intelligent monsters may try to find a way of making it effective again—perhaps by moving it or adding additional features, according to their ability and resources.

When placing traps, think about their purpose in the game and the effect they will have on playing style. Traps are there to increase "the risk of dungeoneering and to encourage skilled play; good dungeons have a judicious mixture of monsters, traps and roleplaying encounters.

Let's consider two OSRIC GMs. One likes to use many traps, some of which cause instant death with no save, while another prefers to use much fewer traps and always permits a saving throw.

The first GM's players will adapt. They will move slowly and carefully through the dungeon, and may have summoned creatures or created zombies to move ahead of them; triggering any traps they might encounter. They will tend to capture prisoners and question them under //charm// or some similar magic about the dungeon environment, and evil aligned characters may use captives like mining canaries. The pace of play will be slow owing to the characters' caution.

The second GM's players will tend not to be thieves. They will move more rapidly through the dungeon to try to achieve surprise against any foes they might encounter, and the game will have a more heroic feel to it.

Decide which style of game suits you and your group and design traps in your dungeons accordingly.

Random Trap Generation

1-2acid spray51-52oil-filled pit with dropping lit torch
3-4bolt, crossbow53-54pit trap triggered by false door
5-6bridge, collapsing55-56pit with dropping ceiling block
7-8bridge, illusory57-58pit with locking trap door
9-10caltrops drop from ceiling59-60pit, 10-ft
11-12ceiling block drops behind players61-62poisoned bolt, crossbow
13-14ceiling blocks drop in front of and behind players63-64poisoned caltrops
15-16ceiling block drops in front of players65-66poisoned spear, ballista
17-18ceiling block drops on players67-68poisoned spike pit
19-20ceiling block seals players in room or area69-70portcullis drops behind players
21-22elevator room71-72portcullises drop in front of and behind players
23-24elevator room, deactivates for 24 hours73-74portcullis drops in front of players
25-26elevator room, one way75-76rolling stone ball, height and width of corridor
27-28falling door77-78scything blade, ankle-high
29-30flame jets79-80scything blade, neck-high
31-32flooding room81-82sliding room changes facing or location
33-34gas, blinding83-84spear, ballista
35-36gas, fear85-86spiked log trap
37-38gas, flammable87-88spiked pit
39-40gas, sleep89-90spring-loaded pile-driver disguised as a door
41-42gas, slowing91-92stairs fold flat into a sliding chute
43-44greased chute93-94stairs collapse
45-46lightning bolt95-96teleporter
47-48log trap, swinging97-98trip wire
49-50obscuring fog99-00wire, neck high


Tricks make something harmless appear dangerous, or make something dangerous appear harmless. Create an expectation but fulfil it in an entirely extraordinary manner: an expensive diamond ring resting in a sturdy lead coffer, or is it? The ring is a well made but worthless trinket, the box is solid gold painted to appear as lead. This is the essence of the trick. Use the two tables below to generate random tricks. The first table will generate a mundane object commonly found in most dungeons, and the second will provide an unexpected attribute.


27-30force field77-80room

*Any: jar, box, coffer, chest, barrel, vase, casket, etc.

**Any door: secret, concealed, valve, arch, etc.


1ages51increases Dexterity
2animated52increases Intelligence
3anti-Magic53increases Strength
4appearing54increases Wisdom
7changes class57laughs
8changes minds from one body to another58magnetic
9changes sex59makes younger
11combination61null gravity
13decreases Charisma63opposite alignment
14decreases Constitution64pivots
15decreases Dexterity65plays games
16decreases Intelligence66points
17decreases Strength67poison
18decreases Wisdom68polymorphing
19directs69random alignment
20disappearing70randomly acts
22dispenses coins72repellent/repulses
23dispenses counterfeit coins73resists magic
24dispenses counterfeit gems74reverse gravity
25dispenses counterfeit jewellery75reverse wish fulfilment
26dispenses counterfeit magic item76riddles
27dispenses counterfeit map77rising
28dispenses gems78rolls
29dispenses jewellery79shifting
30dispenses magic item80shoots
31dispenses map81sings
32distorted depth82sinking
33distorted height83sliding
34distorted length84sloping
35distorted width85spinning
36electric shock86steals
38enrages88suspends animation
40flesh to stone90takes
42fruit92talks in poetry and rhymes
43gaseous93talks nonsense
44geas94talks very intelligently
45gravity decreased95talks, spell casting
46gravity increased96teleports
47greed inducing97unusual colour/texture material
48hovers98variable gravity
49increases Charisma99wish fulfilment
50increases Constitution00yells and screams

Example of use: Gina the GM needs a trick to round out a dungeon map. Taking her trusty d% in hand, she rolls a 37 on the feature table and a 55 on the attribute table. This yields a result of idol, intelligent. She decides the room will contain a carved idol which holds the mind and soul of a long departed adventurer. The idol knows something of the surrounding dungeon rooms but not much else. Depending on how the party approaches and treats with the idol, it may relate some of its knowledge to them.

Gina decides to roll a second trick for a different room and rolls a 25 then 31, which yields a result of fireplace, dispenses map. She places an unlit fireplace in the room in question that has a rolled up map of the next level down hidden among the logs stacked neatly within.