Running the Game

Running the Game

Chapter 15: Running the Game

This section contains rules that help will help Dungeon Masters run the game. For more information to help with being a Dungeon Master, see the Dungeon Master's Guide.

Objects

When characters need to saw through ropes, shatter a window, or smash a vampire's coffin, the only hard and fast rule is this: given enough time and the right tools, characters can destroy any destructible object.

Use common sense when determining a character's success at damaging an object. Can a fighter cut through a section of a stone wall with a sword? No, the sword is likely to break before the wall does.

For the purpose of these rules, an object is a discrete, inanimate item like a window, door, sword, book, table, chair, or stone, not a building or a vehicle that is composed of many other objects.

Statistics for Objects

When time is a factor, you can assign an Armor Class and hit points to a destructible object. You can also give it immunities, resistances, and vulnerabilities to specific types of damage.

Armor Class

An object's Armor Class is a measure of how difficult it is to deal damage to the object when striking it (because the object has no chance of dodging out of the way). The Object Armor Class table provides suggested AC values for various substances.

Substance AC
Cloth, paper, rope 11
Crystal, glass, ice 13
Wood, bone 15
Stone 17
Iron, steel 19
Mithral 21
Adamantine 23

Hit Points

An object's hit points measure how much damage it can take before losing its structural integrity. Resilient objects have more hit points than fragile ones. Large objects also tend to have more hit points than small ones, unless breaking a small part of the object is just as effective as breaking the whole thing. The Object Hit Points table provides suggested hit points for fragile and resilient objects that are Large or smaller.

Size Fragile Resilient
Tiny (bottle, lock) 2 (1d4) 5 (2d4)
Small (chest, lute) 3 (1d6) 10 (3d6)
Medium (barrel, chandelier) 4 (1d8) 18 (4d8)
Large (Cart, 10-ft.-by-10-ft. window) 5 (1d10) 27 (5d10)

Huge and Gargantuan Objects

Normal weapons are of little use against many Huge and Gargantuan objects, such as a colossal statue, towering column of stone, or massive boulder. That said, one torch can burn a Huge tapestry, and an earthquake spell can reduce a colossus to rubble. You can track a Huge or Gargantuan object's hit points if you like, or you can simply decide how long the object can withstand whatever weapon or force is acting against it. If you track hit points for the object, divide it into Large or smaller sections, and track each section's hit points separately. Destroying one of those sections could ruin the entire object. For example, a Gargantuan statue of a human might topple over when one of its Large legs is reduced to 0 hit points.

Objects and Damage Types

Objects are immune to poison and psychic damage. You might decide that some damage types are more effective against a particular object or substance than others. For example, bludgeoning damage works well for smashing things but not for cutting through rope or leather. Paper or cloth objects might be vulnerable to fire and lightning damage. A pick can chip away stone but can't effectively cut down a tree. As always, use your best judgment.

Damage Threshold

Big objects such as castle walls often have extra resilience represented by a damage threshold. An object with a damage threshold has immunity to all damage unless it takes an amount of damage from a single attack or effect equal to or greater than its damage threshold, in which case it takes damage as normal. Any damage that fails to meet or exceed the object's damage threshold is considered superficial and doesn't reduce the object's hit points.

Traps

Traps can be found almost anywhere. One wrong step in an ancient tomb might trigger a series of scything blades, which cleave through armor and bone. The seemingly innocuous vines that hang over a cave entrance might grasp and choke anyone who pushes through them. A net hidden among the trees might drop on travelers who pass underneath. In a fantasy game, unwary adventurers can fall to their deaths, be burned alive, or fall under a fusillade of poisoned darts.

A trap can be either mechanical or magical in nature. Mechanical traps include pits, arrow traps, falling blocks, water-filled rooms, whirling blades, and anything else that depends on a mechanism to operate. Magic traps are either magical device traps or spell traps. Magical device traps initiate spell effects when activated. Spell traps are spells such as glyph of warding and symbol that function as traps.

Traps in Play

When adventurers come across a trap, you need to know how the trap is triggered and what it does, as well as the possibility for the characters to detect the trap and to disable or avoid it.

Triggering a Trap

Most traps are triggered when a creature goes somewhere or touches something that the trap's creator wanted to protect. Common triggers include stepping on a pressure plate or a false section of floor, pulling a trip wire, turning a doorknob, and using the wrong key in a lock. Magic traps are often set to go off when a creature enters an area or touches an object. Some magic traps (such as the glyph of warding spell) have more complicated trigger conditions, including a password that prevents the trap from activating.

Detecting and Disabling a Trap

Usually, some element of a trap is visible to careful inspection. Characters might notice an uneven flagstone that conceals a pressure plate, spot the gleam of light off a trip wire, notice small holes in the walls from which jets of flame will erupt, or otherwise detect something that points to a trap's presence.

A trap's description specifies the checks and DCs needed to detect it, disable it, or both. A character actively looking for a trap can attempt a Wisdom (Perception) check against the trap's DC. You can also compare the DC to detect the trap with each character's passive Wisdom (Perception) score to determine whether anyone in the party notices the trap in passing. If the adventurers detect a trap before triggering it, they might be able to disarm it, either permanently or long enough to move past it. You might call for an Intelligence (Investigation) check for a character to deduce what needs to be done, followed by a Dexterity check using thieves' tools to perform the necessary sabotage.

Any character can attempt an Intelligence (Arcana) check to detect or disarm a magic trap, in addition to any other checks noted in the trap's description. The DCs are the same regardless of the check used. In addition, dispel magic has a chance of disabling most magic traps. A magic trap's description provides the DC for the ability check made when you use dispel magic.

In most cases, a trap's description is clear enough that you can adjudicate whether a character's actions locate or foil the trap. As with many situations, you shouldn't allow die rolling to override clever play and good planning. Use your common sense, drawing on the trap's description to determine what happens. No trap's design can anticipate every possible action that the characters might attempt.

You should allow a character to discover a trap without making an ability check if an action would clearly reveal the trap's presence. For example, if a character lifts a rug that conceals a pressure plate, the character has found the trigger and no check is required.

Foiling traps can be a little more complicated. Consider a trapped treasure chest. If the chest is opened without first pulling on the two handles set in its sides, a mechanism inside fires a hail of poison needles toward anyone in front of it. After inspecting the chest and making a few checks, the characters are still unsure if it's trapped. Rather than simply open the chest, they prop a shield in front of it and push the chest open at a distance with an iron rod. In this case, the trap still triggers, but the hail of needles fires harmlessly into the shield.

Traps are often designed with mechanisms that allow them to be disarmed or bypassed. Intelligent monsters that place traps in or around their lairs need ways to get past those traps without harming themselves. Such traps might have hidden levers that disable their triggers, or a secret door might conceal a passage that goes around the trap.

Trap Effects

The effects of traps can range from inconvenient to deadly, making use of elements such as arrows, spikes, blades, poison, toxic gas, blasts of fire, and deep pits. The deadliest traps combine multiple elements to kill, injure, contain, or drive off any creature unfortunate enough to trigger them. A trap's description specifies what happens when it is triggered.

The attack bonus of a trap, the save DC to resist its effects, and the damage it deals can vary depending on the trap's severity. Use the Trap Save DCs and Attack Bonuses table and the Damage Severity by Level table for suggestions based on three levels of trap severity.

A trap intended to be a setback is unlikely to kill or seriously harm characters of the indicated levels, whereas a dangerous trap is likely to seriously injure (and potentially kill) characters of the indicated levels. A deadly trap is likely to kill characters of the indicated levels.

Trap Save DCs and Attack Bonuses
Trap Danger Save DC Attack Bonus
Setback 10-11 +3 to +5
Dangerous 12-15 +6 to +8
Deadly 16-20 +9 to +12
Damage Severity by Level
Character Level Setback Dangerous Deadly
1st-4th 1d10 2d10 4d10
5th-10th 2d10 4d10 10d10
11th-16th 4d10 10d10 18d10
17th-20th 10d10 18d10 24d10

Complex Traps

Complex traps work like standard traps, except once activated they execute a series of actions each round. A complex trap turns the process of dealing with a trap into something more like a combat encounter.

When a complex trap activates, it rolls initiative. The trap's description includes an initiative bonus. On its turn, the trap activates again, often taking an action. It might make successive attacks against intruders, create an effect that changes over time, or otherwise produce a dynamic challenge. Otherwise, the complex trap can be detected and disabled or bypassed in the usual ways.

For example, a trap that causes a room to slowly flood works best as a complex trap. On the trap's turn, the water level rises. After several rounds, the room is completely flooded.

Sample Traps

The magical and mechanical traps presented here vary in deadliness and are presented in alphabetical order.

Collapsing Roof

Mechanical trap

This trap uses a trip wire to collapse the supports keeping an unstable section of a ceiling in place.

The trip wire is 3 inches off the ground and stretches between two support beams. The DC to spot the trip wire is 10. A successful DC 15 Dexterity check using thieves' tools disables the trip wire harmlessly. A character without thieves' tools can attempt this check with disadvantage using any edged weapon or edged tool. On a failed check, the trap triggers.

Anyone who inspects the beams can easily determine that they are merely wedged in place. As an action, a character can knock over a beam, causing the trap to trigger.

The ceiling above the trip wire is in bad repair, and anyone who can see it can tell that it's in danger of collapse.

When the trap is triggered, the unstable ceiling collapses. Any creature in the area beneath the unstable section must succeed on a DC 15 Dexterity saving throw, taking 22 (4d10) bludgeoning damage on a failed save, or half as much damage on a successful one. Once the trap is triggered, the floor of the area is filled with rubble and becomes difficult terrain.

Falling Net

Mechanical trap

This trap uses a trip wire to release a net suspended from the ceiling.

The trip wire is 3 inches off the ground and stretches between two columns or trees. The net is hidden by cobwebs or foliage. The DC to spot the trip wire and net is 10. A successful DC 15 Dexterity check using thieves' tools breaks the trip wire harmlessly. A character without thieves' tools can attempt this check with disadvantage using any edged weapon or edged tool. On a failed check, the trap triggers.

When the trap is triggered, the net is released, covering a 10-foot-square area. Those in the area are trapped under the net and restrained, and those that fail a DC 10 Strength saving throw are also knocked prone. A creature can use its action to make a DC 10 Strength check, freeing itself or another creature within its reach on a success. The net has AC 10 and 20 hit points. Dealing 5 slashing damage to the net (AC 10) destroys a 5-foot-square section of it, freeing any creature trapped in that section.

Fire-Breathing Statue

Magic trap

This trap is activated when an intruder steps on a hidden pressure plate, releasing a magical gout of flame from a nearby statue. The statue can be of anything, including a dragon or a wizard casting a spell.

The DC is 15 to spot the pressure plate, as well as faint scorch marks on the floor and walls. A spell or other effect that can sense the presence of magic, such as detect magic, reveals an aura of evocation magic around the statue.

The trap activates when more than 20 pounds of weight is placed on the pressure plate, causing the statue to release a 30-foot cone of fire. Each creature in the fire must make a DC 13 Dexterity saving throw, taking 22 (4d10) fire damage on a failed save, or half as much damage on a successful one.

Wedging an iron spike or other object under the pressure plate prevents the trap from activating. A successful dispel magic (DC 13) cast on the statue destroys the trap.

Pits

Mechanical trap

Four basic pit traps are presented here.

Simple Pit. A simple pit trap is a hole dug in the ground. The hole is covered by a large cloth anchored on the pit's edge and camouflaged with dirt and debris.

The DC to spot the pit is 10. Anyone stepping on the cloth falls through and pulls the cloth down into the pit, taking damage based on the pit's depth (usually 10 feet, but some pits are deeper).

Hidden Pit. This pit has a cover constructed from material identical to the floor around it.

A successful DC 15 Wisdom (Perception) check discerns an absence of foot traffic over the section of floor that forms the pit's cover. A successful DC 15 Intelligence (Investigation) check is necessary to confirm that the trapped section of floor is actually the cover of a pit.

When a creature steps on the cover, it swings open like a trapdoor, causing the intruder to spill into the pit below. The pit is usually 10 or 20 feet deep but can be deeper.

Once the pit trap is detected, an iron spike or similar object can be wedged between the pit's cover and the surrounding floor in such a way as to prevent the cover from opening, thereby making it safe to cross. The cover can also be magically held shut using the arcane lock spell or similar magic.

Locking Pit. This pit trap is identical to a hidden pit trap, with one key exception: the trap door that covers the pit is spring-loaded. After a creature falls into the pit, the cover snaps shut to trap its victim inside.

A successful DC 20 Strength check is necessary to pry the cover open. The cover can also be smashed open. A character in the pit can also attempt to disable the spring mechanism from the inside with a DC 15 Dexterity check using thieves' tools, provided that the mechanism can be reached and the character can see. In some cases, a mechanism (usually hidden behind a secret door nearby) opens the pit.

Spiked Pit. This pit trap is a simple, hidden, or locking pit trap with sharpened wooden or iron spikes at the bottom. A creature falling into the pit takes 11 (2d10) piercing damage from the spikes, in addition to any falling damage. Even nastier versions have poison smeared on the spikes. In that case, anyone taking piercing damage from the spikes must also make a DC 13 Constitution saving throw, taking an 22 (4d10) poison damage on a failed save, or half as much damage on a successful one.

Poison Darts

Mechanical trap

When a creature steps on a hidden pressure plate, poison-tipped darts shoot from spring-loaded or pressurized tubes cleverly embedded in the surrounding walls. An area might include multiple pressure plates, each one rigged to its own set of darts.

The tiny holes in the walls are obscured by dust and cobwebs, or cleverly hidden amid bas-reliefs, murals, or frescoes that adorn the walls. The DC to spot them is 15. With a successful DC 15 Intelligence (Investigation) check, a character can deduce the presence of the pressure plate from variations in the mortar and stone used to create it, compared to the surrounding floor. Wedging an iron spike or other object under the pressure plate prevents the trap from activating. Stuffing the holes with cloth or wax prevents the darts contained within from launching.

The trap activates when more than 20 pounds of weight is placed on the pressure plate, releasing four darts. Each dart makes a ranged attack with a +8 bonus against a random target within 10 feet of the pressure plate (vision is irrelevant to this attack roll). (If there are no targets in the area, the darts don't hit anything.) A target that is hit takes 2 (1d4) piercing damage and must succeed on a DC 15 Constitution saving throw, taking 11 (2d10) poison damage on a failed save, or half as much damage on a successful one.

Poison Needle

Mechanical trap

A poisoned needle is hidden within a treasure chest's lock, or in something else that a creature might open. Opening the chest without the proper key causes the needle to spring out, delivering a dose of poison.
When the trap is triggered, the needle extends 3 inches straight out from the lock. A creature within range takes 1 piercing damage and 11 (2d10) poison damage, and must succeed on a DC 15 Constitution saving throw or be poisoned for 1 hour.

A successful DC 20 Intelligence (Investigation) check allows a character to deduce the trap's presence from alterations made to the lock to accommodate the needle. A successful DC 15 Dexterity check using thieves' tools disarms the trap, removing the needle from the lock. Unsuccessfully attempting to pick the lock triggers the trap.

Rolling Sphere

Mechanical trap

When 20 or more pounds of pressure are placed on this trap's pressure plate, a hidden trapdoor in the ceiling opens, releasing a 10-foot-diameter rolling sphere of solid stone.

With a successful DC 15 Wisdom (Perception) check, a character can spot the trapdoor and pressure plate. A search of the floor accompanied by a successful DC 15 Intelligence (Investigation) check reveals variations in the mortar and stone that betray the pressure plate's presence. The same check made while inspecting the ceiling notes variations in the stonework that reveal the trapdoor. Wedging an iron spike or other object under the pressure plate prevents the trap from activating.

Activation of the sphere requires all creatures present to roll initiative. The sphere rolls initiative with a +8 bonus. On its turn, it moves 60 feet in a straight line. The sphere can move through creatures' spaces, and creatures can move through its space, treating it as difficult terrain. Whenever the sphere enters a creature's space or a creature enters its space while it's rolling, that creature must succeed on a DC 15 Dexterity saving throw or take 55 (10d10) bludgeoning damage and be knocked prone.

The sphere stops when it hits a wall or similar barrier. It can't go around corners, but smart dungeon builders incorporate gentle, curving turns into nearby passages that allow the sphere to keep moving.

As an action, a creature within 5 feet of the sphere can attempt to slow it down with a DC 20 Strength check. On a successful check, the sphere's speed is reduced by 15 feet. If the sphere's speed drops to 0, it stops moving and is no longer a threat.

Sphere of Annihilation

Magic trap

Magical, impenetrable darkness fills the gaping mouth of a stone face carved into a wall. The mouth is 2 feet in diameter and roughly circular. No sound issues from it, no light can illuminate the inside of it, and any matter that enters it is instantly obliterated.

A successful DC 20 Intelligence (Arcana) check reveals that the mouth contains a sphere of annihilation that can't be controlled or moved. It is otherwise identical to a normal sphere of annihilation.

Some versions of the trap include an enchantment placed on the stone face, such that specified creatures feel an overwhelming urge to approach it and crawl inside its mouth. This effect is otherwise like the sympathy aspect of the antipathy/sympathy spell. A successful dispel magic (DC 18) removes this enchantment.

Poisons

Given their insidious and deadly nature, poisons are illegal in most societies but are a favorite tool among assassins, drow, and other evil creatures.

Poison Types

Poisons come in the following four types.

Contact. Contact poison can be smeared on an object and remains potent until it is touched or washed off. A creature that touches contact poison with exposed skin suffers its effects.

Ingested. A creature must swallow an entire dose of ingested poison to suffer its effects. The dose can be delivered in food or a liquid. You may decide that a partial dose has a reduced effect, such as allowing advantage on the saving throw or dealing only half damage on a failed save.

Inhaled. These poisons are powders or gases that take effect when inhaled. Blowing the powder or releasing the gas subjects creatures in a 5-foot cube to its effect. The resulting cloud dissipates immediately afterward. Holding one's breath is ineffective against inhaled poisons, as they affect nasal membranes, tear ducts, and other parts of the body.

Injury. Injury poison can be applied to weapons, ammunition, trap components, and other objects that deal piercing or slashing damage and remains potent until delivered through a wound or washed off. A creature that takes piercing or slashing damage from an object coated with the poison is exposed to its effects.

 Sample Poisons

Item Type Price per Dose
Assassin's blood Ingested 150 gp
Burnt othur fumes Inhaled 500 gp
Crawler mucus Contact 200 gp
Drow poison Injury 200 gp
Essence of ether Inhaled 300 gp
Malice Inhaled 250 gp
Midnight tears Ingested 1,500 gp
Oil of taggit Contact 400 gp
Pale tincture Ingested 250 gp
Purple worm poison Injury 2,000 gp
Serpent venom Injury 200 gp
Torpor Ingested 600 gp
Truth serum Ingested 150 gp
Wyvern poison Injury 1,200 gp

Poison Descriptions

Each type of poison has its own debilitating effects.

Assassin's Blood (Ingested). A creature subjected to this poison must make a DC 10 Constitution saving throw. On a failed save, it takes 6 (1d12) poison damage and is poisoned for 24 hours. On a successful save, the creature takes half damage and isn't poisoned.

Burnt Othur Fumes (Inhaled). A creature subjected to this poison must succeed on a DC 13 Constitution saving throw or take 10 (3d6) poison damage, and must repeat the saving throw at the start of each of its turns. On each successive failed save, the character takes 3 (1d6) poison damage. After three successful saves, the poison ends.

Crawler Mucus (Contact). This poison must be harvested from a dead or incapacitated crawler. A creature subjected to this poison must succeed on a DC 13 Constitution saving throw or be poisoned for 1 minute. The poisoned creature is paralyzed. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Drow Poison (Injury). This poison is typically made only by the drow, and only in a place far removed from sunlight. A creature subjected to this poison must succeed on a DC 13 Constitution saving throw or be poisoned for 1 hour. If the saving throw fails by 5 or more, the creature is also unconscious while poisoned in this way. The creature wakes up if it takes damage or if another creature takes an action to shake it awake.

Essence of Ether (Inhaled). A creature subjected to this poison must succeed on a DC 15 Constitution saving throw or become poisoned for 8 hours. The poisoned creature is unconscious. The creature wakes up if it takes damage or if another creature takes an action to shake it awake.

Malice (Inhaled). A creature subjected to this poison must succeed on a DC 15 Constitution saving throw or become poisoned for 1 hour. The poisoned creature is blinded.

Midnight Tears (Ingested). A creature that ingests this poison suffers no effect until the stroke of midnight. If the poison has not been neutralized before then, the creature must succeed on a DC 17 Constitution saving throw, taking 31 (9d6) poison damage on a failed save, or half as much damage on a successful one.

Oil of Taggit (Contact). A creature subjected to this poison must succeed on a DC 13 Constitution saving throw or become poisoned for 24 hours. The poisoned creature is unconscious. The creature wakes up if it takes damage.

Pale Tincture (Ingested). A creature subjected to this poison must succeed on a DC 16 Constitution saving throw or take 3 (1d6) poison damage and become poisoned. The poisoned creature must repeat the saving throw every 24 hours, taking 3 (1d6) poison damage on a failed save. Until this poison ends, the damage the poison deals can't be healed by any means. After seven successful saving throws, the effect ends and the creature can heal normally.

Purple Worm Poison (Injury). This poison must be harvested from a dead or incapacitated purple worm. A creature subjected to this poison must make a DC 19 Constitution saving throw, taking 42 (12d6) poison damage on a failed save, or half as much damage on a successful one.

Serpent Venom (Injury). This poison must be harvested from a dead or incapacitated giant poisonous snake. A creature subjected to this poison must succeed on a DC 11 Constitution saving throw, taking 10 (3d6) poison damage on a failed save, or half as much damage on a successful one.

Torpor (Ingested). A creature subjected to this poison must succeed on a DC 15 Constitution saving throw or become poisoned for 4d6 hours. The poisoned creature is incapacitated.

Truth Serum (Ingested). A creature subjected to this poison must succeed on a DC 11 Constitution saving throw or become poisoned for 1 hour. The poisoned creature can't knowingly speak a lie, as if under the effect of a zone of truth spell.

Wyvern Poison (Injury). This poison must be harvested from a dead or incapacitated wyvern. A creature subjected to this poison must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Diseases

A plague ravages the kingdom, setting the adventurers on a quest to find a cure. An adventurer emerges from an ancient tomb, unopened for centuries, and soon finds herself suffering from a wasting illness. A warlock offends some dark power and contracts a strange affliction that spreads whenever he casts spells.

A simple outbreak might amount to little more than a small drain on party resources, curable by a casting of lesser restoration. A more complicated outbreak can form the basis of one or more adventures as characters search for a cure, stop the spread of the disease, and deal with the consequences.

A disease that does more than infect a few party members is primarily a plot device. The rules help describe the effects of the disease and how it can be cured, but the specifics of how a disease works aren't bound by a common set of rules. Diseases can affect any creature, and a given illness might or might not pass from one race or kind of creature to another. A plague might affect only constructs or undead, or sweep through a halfling neighborhood but leave other races untouched. What matters is the story you want to tell.

Sample Diseases

The diseases here illustrate the variety of ways disease can work in the game. Feel free to alter the saving throw DCs, incubation times, symptoms, and other characteristics of these diseases to suit your campaign.

Cackle Fever

This disease targets humanoids, although gnomes are strangely immune. While in the grips of this disease, victims frequently succumb to fits of mad laughter, giving the disease its common name and its morbid nickname: "the shrieks."

Symptoms manifest 1d4 hours after infection and include fever and disorientation. The infected creature gains one level of exhaustion that can't be removed until the disease is cured.

Any event that causes the infected creature great stress--including entering combat, taking damage, experiencing fear, or having a nightmare--forces the creature to make a DC 13 Constitution saving throw. On a failed save, the creature takes 5 (1d10) psychic damage and becomes incapacitated with mad laughter for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the mad laughter and the incapacitated condition on a success.

Any humanoid creature that starts its turn within 10 feet of an infected creature in the throes of mad laughter must succeed on a DC 10 Constitution saving throw or also become infected with the disease. Once a creature succeeds on this save, it is immune to the mad laughter of that particular infected creature for 24 hours.

At the end of each long rest, an infected creature can make a DC 13 Constitution saving throw. On a successful save, the DC for this save and for the save to avoid an attack of mad laughter drops by 1d6. When the saving throw DC drops to 0, the creature recovers from the disease. A creature that fails three of these saving throws gains a randomly determined form of indefinite madness, as described in the "Madness" section.

Sewer Plague

Sewer plague is a generic term for a broad category of illnesses that incubate in sewers, refuse heaps, and stagnant swamps, and which are sometimes transmitted by creatures that dwell in those areas, such as rats and otyughs.

When a humanoid creature is bitten by a creature that carries the disease, or when it comes into contact with filth or offal contaminated by the disease, the creature must succeed on a DC 11 Constitution saving throw or become infected.

It takes 1d4 days for sewer plague's symptoms to manifest in an infected creature. Symptoms include fatigue and cramps. The infected creature suffers one level of exhaustion, and it regains only half the normal number of hit points from spending Hit Dice and no hit points from finishing a long rest.

At the end of each long rest, an infected creature must make a DC 11 Constitution saving throw. On a failed save, the character gains one level of exhaustion. On a successful save, the character's exhaustion level decreases by one level. If a successful saving throw reduces the infected creature's level of exhaustion below 1, the creature recovers from the disease.

Sight Rot

This painful infection causes bleeding from the eyes and eventually blinds the victim.

A beast or humanoid that drinks water tainted by sight rot must succeed on a DC 15 Constitution saving throw or become infected. One day after infection, the creature's vision starts to become blurry. The creature takes a −1 penalty to attack rolls and ability checks that rely on sight. At the end of each long rest after the symptoms appear, the penalty worsens by 1. When it reaches −5, the victim is blinded until its sight is restored by magic such as lesser restoration or heal.

Sight rot can be cured using a rare flower called Eyebright, which grows in some swamps. Given an hour, a character who has proficiency with an herbalism kit can turn the flower into one dose of ointment. Applied to the eyes before a long rest, one dose of it prevents the disease from worsening after that rest. After three doses, the ointment cures the disease entirely.

Madness

In a typical campaign, characters aren't driven mad by the horrors they face and the carnage they inflict day after day, but sometimes the stress of being an adventurer can be too much to bear. If your campaign has a strong horror theme, you might want to use madness as a way to reinforce that theme, emphasizing the extraordinarily horrific nature of the threats the adventurers face.

Going Mad

Various magical effects can inflict madness on an otherwise stable mind. Certain spells, such as contact other plane and symbol, can cause insanity, and you can use the madness rules here instead of the spell effects of those spells. Diseases, poisons, and planar effects such as psychic wind or the howling winds of Pandemonium can all inflict madness. Some artifacts can also break the psyche of a character who uses or becomes attuned to them.

Resisting a madness-inducing effect usually requires a Wisdom or Charisma saving throw.

Madness Effects

Madness can be short-term, long-term, or indefinite. Most relatively mundane effects impose short-term madness, which lasts for just a few minutes. More horrific effects or cumulative effects can result in long-term or indefinite madness.

A character afflicted with short-term madness is subjected to an effect from the Short-Term Madness table for 1d10 minutes.

A character afflicted with long-term madness is subjected to an effect from the Long-Term Madness table for 1d10 × 10 hours.

A character afflicted with indefinite madness gains a new character flaw from the Indefinite Madness table that lasts until cured.

Short-Term Madness

d100 Effect (lasts 1d10 minutes)
01-20 The character retreats into his or her mind and becomes paralyzed. The effect ends if the character takes any damage.
21-30 The character becomes incapacitated and spends the duration screaming, laughing, or weeping.
31-40 The character becomes frightened and must use his or her action and movement each round to flee from the source of the fear.
41-50 The character begins babbling and is incapable of normal speech or spellcasting.
51-60 The character must use his or her action each round to attack the nearest creature.
61-70 The character experiences vivid hallucinations and has disadvantage on ability checks.
71-75 The character does whatever anyone tells him or her to do that isn't obviously self-destructive.
76-80 The character experiences an overpowering urge to eat something strange such as dirt, slime, or offal.
81-90 The character is stunned.
91-100 The character falls unconscious.

Long-Term Madness

d100 Effect (lasts 1d10 x 10 hours)
01-10 The character feels compelled to repeat a specific activity over and over, such as washing hands, touching things, praying, or counting coins.
11-20 The character experiences vivid hallucinations and has disadvantage on ability checks.
21-30 The character suffers extreme paranoia. The character has disadvantage on Wisdom and Charisma checks.
31-40 The character regards something (usually the source of madness) with intense revulsion, as if affected by the antipathy effect of the antipathy/sympathy spell.
41-45 The character experiences a powerful delusion. Choose a potion. The character imagines that he or she is under its effects.
46-55 The character becomes attached to a "lucky charm," such as a person or an object, and has disadvantage on attack rolls, ability checks, and saving throws while more than 30 feet from it.
56-65 The character is blinded (25%) or deafened (75%).
66-75 The character experiences uncontrollable tremors or tics, which impose disadvantage on attack rolls, ability checks, and saving throws that involve Strength or Dexterity.
76-85 The character suffers from partial amnesia. The character knows who he or she is and retains racial traits and class features, but doesn't recognize other people or remember anything that happened before the madness took effect.
86-90 Whenever the character takes damage, he or she must succeed on a DC 15 Wisdom saving throw or be affected as though he or she failed a saving throw against the confusion spell. The confusion effect lasts for 1 minute.
91-95 The character loses the ability to speak.
96-100 The character falls unconscious. No amount of jostling or damage can wake the character.

Indefinite Madness

d100 Flaw (lasts until cured)
01-15 "Being drunk keeps me sane."
16-25 "I keep whatever I find."
26-30 "I try to become more like someone else I know--adopting his or her style of dress, mannerisms, and name."
31-35 "I must bend the truth, exaggerate, or outright lie to be interesting to other people."
36-45 "Achieving my goal is the only thing of interest to me, and I'll ignore everything else to pursue it."
46-50 "I find it hard to care about anything that goes on around me."
51-55 "I don't like the way people judge me all the time."
56-70 "I am the smartest, wisest, strongest, fastest, and most beautiful person I know."
71-80 "I am convinced that powerful enemies are hunting me, and their agents are everywhere I go. I am sure they're watching me all the time."
81-85 "There's only one person I can trust. And only I can see this special friend."
86-95 "I can't take anything seriously. The more serious the situation, the funnier I find it."
96-100 "I've discovered that I really like killing people."

Curing Madness

A calm emotions spell can suppress the effects of madness, while a lesser restoration spell can rid a character of a short-term or long-term madness. Depending on the source of the madness, remove curse or dispel evil and good might also prove effective. A greater restoration spell or more powerful magic is required to rid a character of indefinite madness.