Traps are the bane of adventurers and rightly so. The builder of a trap seeks to deter or destroy those that would intrude into their domain or protect valuables from all who might seek to steal them.

Because traps usually require some expense/effort to build and maintain, the builder much make decisions regarding the placement and management of any particular trap according to their resources. That said, trap builders do not hold back and will create the deadliest traps available within their set of resources.

Thus, traps represent something of a conundrum to the Game Master. While dungeon areas can be designed with player levels in mind, how is one to adjudicate the placement of traps when lethality can far outstrip the creatures surrounding it? By using common sense:

1. Traps are built with the least expense to do the job.

2. Traps are constructed with the most likely type of intruder in mind.

3. Traps are typically made to be reset or maintained which will limit the complexity of the trap.

4. Normally, traps will be constructed with materials readily available to the builder.

Thus, while exceptions will exist for particularly valuable treasures or important areas, using the strictures above will have a natural level-limiting effect based upon the foes faced.

In addition, while the effect of a trap can become more dangerous and, in rare circumstances, harder to detect, adventurers possess a number of ways to detect traps particularly as they rise in levels of experience. At higher levels, traps are mainly dangerous to the foolish or unwary.

TYPES OF TRAPS

Traps come in a number of diabolically creative forms, but the primary types are:

1. Confining traps. These traps seek to immobilize they prey so that they may be dealt with later.

2. Channeling traps. These traps seek to funnel the prey toward an area. Perhaps toward another trap or toward a dangerous guardian. These include blocking-type traps that close off an avenue of escape without total confinement.

3. Injuring traps. These traps seeks to cause harm in hopes of killing but without a “save or die” component. These may also include traps designed to cause attrition in terms of intruder resources, damage equipment or the like.

4. Killing traps. These traps are designed to kill as efficiently as possible, classically with poison or similar “save or die” methods.

Tricks. Similar to a trap, a “trick” is designed to foil the intention of the intruder with varying degrees of lethality. In these cases, a builder may be seeking to allow only those worthy to proceed. In others, the builder seeks to fool the intruder into believing something false, thus protecting the real item, creature or area.

Hazards. Sometimes, the builder uses either natural or manufactured areas that present a danger due to their very nature, like a crevasse or a slippery ledge. Otherwise, the builder may lure or cultivate certain creatures or organisms to present a threat such as green slime, the presence of piercers, or monstrous fungi.

EXAMPLE TRAPS

The following are a list of common traps and their attributes, helpful to game masters in the creation of encounters and thieves or others intent on building their own traps.

Arrow Trap. This trap fires a projectile at the intruder. Detection. The trap can be found by those using the find traps skill or those noticing a hole, tripwire or similar (20% chance or better if an elf/half-elf if examining an area using Thorough Examination). Trigger. The trigger is usually tied to a creature’s location or manipulation of some object. Effect. The trap typically involves a crossbow-type device and uses an attack roll against a victim’s armor class (using surprise, facing rules, and armor defense adjustment as applicable). Simple traps will normally attack as a 4 HD creature (AAC0 15) and do 1d4+1 damage if they strike. Variations. Traps can fire multiple projectiles, or be equipped with darts, spikes, or even ballista-sized equipped with spears. Ammunition can be poisoned or have other effects. The projectile can be a scything blade and, if expertly crafted or magic is involved, can include the loss of an appendage. Similarly, expertly crafted or magically enhanced traps can increase the probability of the attack roll. Cost. Approximately 50 g.p. for a basic version involving a heavy crossbow with simple concealment (e.g. a curtain) and trigger (wire). Otherwise, additional stonework could run up to 200 g.p. or more for less detectable triggers such as pressure-plates or device placement behind special walls. Construction Time. 1-2 hours for a basic version assuming materials are on hand. Reset. The trap can be manually reset for no additional cost.

Blocking Trap. This trap drops a blocking device to channel or confine an intruder. Detection. The trap can typically only be found using a find traps skill, although cheap triggers (trip wires) may be located using other means. Trigger. The trigger is typically a pressure plate or object to be interacted with (door or container), although cheaper versions may use a trip wire. Effect. A door, stone block, or gate falls, closing off an avenue of escape. A creature directly underneath the falling object can make a Dexterity save vs. Petrify to avoid damage and choose which side of the object they leap. Otherwise they will take damage (2d6 for doors/gates and much more for stone blocks, e.g. 3d10 with a natural 1 on the save indicating a crushing death). Variations. Sometimes the blocking device is dropped on a grade, and rolls down the grade, crushing any along the way (save for half)—those with fast movement may be able to outrun it (although the trap may seek to channel the runners into another trap or dangerous area). Liquid can be used in a similar manner (rushing water or lava). Some versions will include an audible warning (more than the clanging enclosure) to bring guards or predators. Cost. 200-400 g.p. for a basic door/gate depending upon materials, trigger, and area size. Multiply by 10 for immense blocks of stone or the like (requiring special talents or magic). Construction Time. Approximately 1 week if materials are on hand for basic versions. Otherwise, 1-2 months. Reset. A door/gate can be reset in about 10 minutes assuming good construction. Large stone traps typically cannot be reset.

Gas Trap. This trap releases a volume of gas in order to affect one or more creatures nearby. Detection. The trap can typically only be found using a find traps skill, although cheaply made enclosures might be detectable based on noticing a special insulation (via Thorough Examination). Some such traps might be constructed without a means of detection, although, typically, if tied to an enclosure, detection can occur through careful manipulation. Effect. A puff of gas is emitted by breaking the seal or, more commonly, the breaking of a glass container holding the gas when an enclosure is opened. The gas may affect any creature standing in an adjacent 5-ft. area around the enclosure. Typical versions of the gas are an inhaled poison. See Poison. Variations. Larger volumes of gas might be designed. The gas can be magical (e.g. sleep) or even the result of a dormant colony of monstrous mold (e.g. yellow mold). The gas may be ignited in a jet of flame (via a trigger or explosive caused by the presence of torches). Cost. These traps are typically complex and require special expertise (alchemy, poison-expert, glass-blowing, etc.). In addition to double the cost of the poison (for volume), these traps can run upwards of 1,000-2,000 g.p. for a specially designed enclosure which normally will include a bypass. Construction Time. About four weeks unless the gas container and suitable enclosure is already available, then 1 day. Reset. The gas must be replaced at full cost and an expert must re-arm the trap using the set traps skill.

Pit Trap. This trap is normally a covered opening that drops the intruder down a pit when walked over. Detection. The trap can be found by those using the find traps skill or those noticing an outline or hollow floor due to tapping (20% chance or better if an elf/half-elf or dwarf if examining an area using Thorough Examination as described above). Trigger. Walking over a covering. Effect. Any creature weighing more than 30 lbs. has a 50% chance (01-50 on a d100) of triggering the trap door and falling into the pit, taking falling damage (those nearby or walking behind may also have a chance of falling). If precautions are being taken (or alternatively, a surprise roll fails), those falling may make a Dexterity save vs. Petrify to grab an edge and avoid falling. For falling damage see Falling above. Typical depth is 10 to 30 feet. Variations. Deeper pits or those with covers that spring back and lock into place (trapping the fallen). Often, something unpleasant will be at the bottom of the pit rather than a flat floor: spikes (sometimes poisoned), punji sticks, frigid water, acid, green slime, a chute to another area, etc. Cost. A well constructed 20-ft. deep pit with a reusable cover can cost 100-200 g.p. to construct unless experts are available for no cost. Cheaper construction will be less but may be detectable using a tapping stick or Close Observation methods. Construction Time. Similar to dungeon-type construction—about four days per 10-ft. of depth unless mining experts are used. Reset. If well constructed, the trap can be manually reset in 3 minutes by two creatures.

Poison Trap. This trap involves a poisoned needle hidden in a latch, keyhole or similar hidden area. When manipulated, the needle mechanically extends in an attempt to puncture a member and deliver the poison. Detection. The trap can be found by those using the find traps skill. Trigger. If placed in a lock, anyone manipulating the lock without the right key will be subject to the attack. Otherwise, anyone using the handle or latch will be subject to the attack. Effect. Unless a save vs. Poison is successful, the needle hits and delivers the poison successfully. Typically, this is a deadly poison. Variations. The poison can be a less lethal kind or more deadly (see Poison). The trap may not involve a needle but the poison is a contact poison so that any touch will deliver the poison. Cost. A poison needle built into a good quality lock will cost around 100 g.p. for a device that offers the ability to be reset. This includes the expense of the lock itself. See Poison below for poison costs. Construction Time. Building a needle lock will take about 2 weeks by an expert locksmith. Poor quality versions include easy to find passive needles jammed into an existing lock (+50% to find; 50% chance to notice in clear light, and +2 to +4 bonus on the saving throw on top of any poison adjustment). Reset. A quality mechanism can be reset in 5 rounds including (carefully) re-applying the poison. If constructed to be reset, the mechanism does not require the set traps skill to be reset.

Spell Trap. Spell traps include traps that involve a glyph of warding, fire trap, explosive runes, or other spell. These also include magic traps that contain spells or curses to maim, kill or confound intruders. Thus the number of variations of such traps is very high. In any case, these traps, if involving more than a single 5-ft area will begin at 2,000 g.p. (for a typical 3rd-level fire glyph of warding) and get progressively more expensive from there. Thus, they tend to be the most rare and protect only the most important areas. A typical foil to these traps is the fact that a simple detect magic spell can tip off a wary would-be victim.