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

d%	Result	d%	Result
1-2	acid spray	51-52	oil-filled pit with dropping lit torch
3-4	bolt, crossbow	53-54	pit trap triggered by false door
5-6	bridge, collapsing	55-56	pit with dropping ceiling block
7-8	bridge, illusory	57-58	pit with locking trap door
9-10	caltrops drop from ceiling	59-60	pit, 10-ft
11-12	ceiling block drops behind players	61-62	poisoned bolt, crossbow
13-14	ceiling blocks drop in front of and behind players	63-64	poisoned caltrops
15-16	ceiling block drops in front of players	65-66	poisoned spear, ballista
17-18	ceiling block drops on players	67-68	poisoned spike pit
19-20	ceiling block seals players in room or area	69-70	portcullis drops behind players
21-22	elevator room	71-72	portcullises drop in front of and behind players
23-24	elevator room, deactivates for 24 hours	73-74	portcullis drops in front of players
25-26	elevator room, one way	75-76	rolling stone ball, height and width of corridor
27-28	falling door	77-78	scything blade, ankle-high
29-30	flame jets	79-80	scything blade, neck-high
31-32	flooding room	81-82	sliding room changes facing or location
33-34	gas, blinding	83-84	spear, ballista
35-36	gas, fear	85-86	spiked log trap
37-38	gas, flammable	87-88	spiked pit
39-40	gas, sleep	89-90	spring-loaded pile-driver disguised as a door
41-42	gas, slowing	91-92	stairs fold flat into a sliding chute
43-44	greased chute	93-94	stairs collapse
45-46	lightning bolt	95-96	teleporter
47-48	log trap, swinging	97-98	trip wire
49-50	obscuring fog	99-00	wire, neck high

Result:

Tricks

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.

Tricks-features

d%	Feature	d%	Feature
1-3	altar	51-53	monster
4-6	arch	54-56	mosaic
7-10	ceiling	57-60	painting
11-13	container*	61-63	passage
14-16	dome	64-66	pedestal
17-20	door**	67-70	pillar/Column
21-23	fire	71-73	pit
24-26	fireplace	74-76	pool
27-30	force field	77-80	room
31-33	fountain	81-83	stairway
34-36	furnishing	83-86	statue
37-40	idol	87-90	tapestry
41-43	illusion	91-93	vegetation
44-46	machine	94-96	wall
47-50	mirror	97-00	well

Result:

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

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

Tricks—attributes

d%	Feature	d%	Feature
1	ages	51	increases Dexterity
2	animated	52	increases Intelligence
3	anti-Magic	53	increases Strength
4	appearing	54	increases Wisdom
5	asks	55	intelligent
6	attacks	56	invisible
7	changes class	57	laughs
8	changes minds from one body to another	58	magnetic
9	changes sex	59	makes younger
10	collapsing	60	moves
11	combination	61	null gravity
12	dances	62	one-way
13	decreases Charisma	63	opposite alignment
14	decreases Constitution	64	pivots
15	decreases Dexterity	65	plays games
16	decreases Intelligence	66	points
17	decreases Strength	67	poison
18	decreases Wisdom	68	polymorphing
19	directs	69	random alignment
20	disappearing	70	randomly acts
21	disintegrates	71	reduces
22	dispenses coins	72	repellent/repulses
23	dispenses counterfeit coins	73	resists magic
24	dispenses counterfeit gems	74	reverse gravity
25	dispenses counterfeit jewellery	75	reverse wish fulfilment
26	dispenses counterfeit magic item	76	riddles
27	dispenses counterfeit map	77	rising
28	dispenses gems	78	rolls
29	dispenses jewellery	79	shifting
30	dispenses magic item	80	shoots
31	dispenses map	81	sings
32	distorted depth	82	sinking
33	distorted height	83	sliding
34	distorted length	84	sloping
35	distorted width	85	spinning
36	electric shock	86	steals
37	enlarges	87	suggests
38	enrages	88	suspends animation
39	false	89	symbiotic
40	flesh to stone	90	takes
41	foretells	91	talks
42	fruit	92	talks in poetry and rhymes
43	gaseous	93	talks nonsense
44	geas	94	talks very intelligently
45	gravity decreased	95	talks, spell casting
46	gravity increased	96	teleports
47	greed inducing	97	unusual colour/texture material
48	hovers	98	variable gravity
49	increases Charisma	99	wish fulfilment
50	increases Constitution	00	yells and screams

Result:

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.