Your blood does not have the hemoglobin associated with most people. A creature that drinks blood like a vampire or stirge that tries to drink yours must succeed on a DC 8 + (IE) Constitution saving throw on a successful bite attack or experience 2 (1d4) poison damage unless otherwise noted and does not receive the restorative benefits from the attack.

• Acid. Your blood is highly acidic. Every minute of exertion, such as combat, a walking forced march, or climbing, you need to succeed on a DC 5 + (IE) Constitution saving throw, increasing cumulatively by 1 every minute of exertion or take one level of exhaustion until taking a short rest. If collected, a flask of 32 ounces equals one use as a weapon. A creature successfully biting you takes 1d(IE) acid damage.
• Chlorocruorin. Your blood is green and processes oxygen better than usual, but you’re sensitive to cold environments. You can hold your breath an additional (IE) × 10 percent. You take an additional (IE) × 10 percent cold damage and have a −(IE) penalty on Constitution saving throws against extreme cold as outlined in official fifth edition sources. When wearing cold weather gear, you must still make this saving throw, although the cold weather gear grants advantage on the saving throw.
• Coboglobin. Your cobalt-based blood is colorless or amber yellow and does not retain oxygen as well. You are also highly susceptible to cold. You can hold your breath (IE) × 10 percent less than usual, and in low oxygen areas like high altitudes, you must succeed on a DC 8 + (IE) Constitution saving throw every hour or take one level of exhaustion until taking a short rest. You take an additional (IE) × 10 percent cold damage and have a −(IE) penalty on Constitution saving throws against extreme cold as outlined in official fifth edition sources. When wearing cold weather gear, you must still make this saving throw, although the cold weather gear grants advantage on the saving throw. You have a +(IE) bonus to saving throws against extreme heat as outlined in official fifth edition sources.
• Combustible. Your blood contains a volatile chemical combination that, when exposed to oxygen by taking piercing or slashing damage, combusts for 1 round, causing (IE)d4 damage to anyone it touches, including you and any creature that causes the damage with a claw or bite attack.
• Erythrocruorin. Your blood, which has a much higher iron content than usual, is much brighter red than is typical and allows you to process more oxygen at a time. You can hold your breath for IE × 10 percent longer than usual and have a +(IE) bonus to Constitution checks related to exertion. If successfully attacked by a creature that sucks blood, the creature gains an additional (IE) benefit from the bite attack and does not take poison damage.
• Hemerythrin. Your blood is colorless or violet, and you heal faster than usual, receiving a + (IE) × 10 percent (minimum 1) bonus to all healing magic, but you process oxygen less efficiently than typical, so you can hold your breath (IE) × 10 percent less than usual, and in low oxygen areas like high altitudes, you must succeed on a DC 8 + (IE) Constitution saving throw every hour or take one level of exhaustion until taking a short rest. You also have a +(IE) bonus to all saving throws against gas-based poison damage.
• Hemocyanin. Your copper-based blood is colorless or blue and operates best in low-oxygen or cold environments. You can hold your breath an additional (IE) × 10 percent. You have a +(IE) bonus to all saving throws against cold damage. You have a −(IE) penalty on saving throws against extreme heat as outlined in official fifth edition sources. In warm tropical environments, every minute of exertion, such as combat, a walking forced march, or climbing, you need to succeed on a DC 5 + (IE) Constitution saving throw, increasing cumulatively by 1 every minute of exertion or take one level of exhaustion until taking a short rest. Because your blood is colorless or nearly so, anyone attempting to stabilize you while you make death saving throws using first aid has a −(IE) penalty on their Wisdom (Medicine) check.
• Vanabins. Your blood color ranges from deep blue to yellow and uses oxygen extremely efficiently. You can hold your breath for IE × 10 percent longer than usual and have a +(IE) bonus to Constitution checks related to exertion. This increase in metabolism, however, requires more food, so you must eat (IE) × 50 percent more food than usual.
• Volatile Liquid. When your blood, which varies from colorless to yellow, is exposed to air, it instantly evaporates into a toxic gas. You are resistant to it but not immune. All within (IE) × 5 feet must succeed on a DC 8 + (IE) Constitution saving throw or take (IE)d4 poison damage.

Real-world Examples

Acidosis; (Found in animals) Hemerythrin, Vanabins, Chlorocruorin, Erythrocruorin, Hemocyanin

Assistive Options

Assistance for these blood types involve avoiding harmful environments when possible.

Magical Assistance

Magic that provides resistance to cold or fire damage will reduce the temperature sensitivities of blood types as applicable by 2 IEs.

You react to a medicinal or magical effect different from or the opposite of the intended effect. Each time you consume a medication, herbal treatment, or potion, you must succeed on a DC 8 + (IE) Constitution saving throw. On a failed save, roll for an effect on the table below, rerolling effects that don’t make sense, which lasts (IE)d4 hours. If you fail by less than or equal to 5 − (IE), you still gain the intended effect in addition to the random effect. If you’ve succeeded on the saving throw for this substance before, you have advantage on this save. If you’ve failed on the saving throw for this substance before, you have disadvantage on this save.

You have a −(IE) penalty on all saving throws against disease.

Real-world Examples

Addison Disease, Celiac Disease, Dermatomyositis, Graves Disease, Hashimoto Thyroiditis, Multiple Sclerosis, Myasthenia Gravis, Pernicious Anemia, Reactive Arthritis, Rheumatoid Arthritis, Sjögren Syndrome, Systemic Lupus Erythematosus, Diabetes, Down Syndrome

Assistive Options

This is managed by avoiding diseases when possible.

Magical Assistance

Magic that cures diseases can cure a disease once infection happens but cannot be used proactively.

You are infected with a disease but show no symptoms yourself. Choose a disease from official fifth edition sources or another source. You transmit this disease to others via the transmission method associated with it. Anyone who comes into contact with you via its transmission method must succeed on a DC 8 + (IE) Constitution saving throw or become infected.

Real-world Examples

Typhoid Fever, HIV, Epstein–Barr Virus, Clostridioides Difficile, Cholera, Chlamydia, Poliomyelitis, Tuberculosis, COVID-19

Assistive Options

Depending on the method of transmission, taking precautions (e.g., a face mask for air transmission) can give the potential target advantage on the Constitution saving throw.

Magical Assistance

Magic that cures diseases can eliminate this condition, but anytime you need to make a saving throw against disease, unless you succeed by at least 5, you become an Atraitatic Disease Carrier of the new disease.

Your body has a negative reaction to a stimulus or group of stimuli. While all have a Triggered Frequency, some can seem periodic due to the nature of the stimulus, especially seasonal allergies. You have 1d4 of the following allergies.

• Food Allergy. You are allergic to ingesting certain foods. If you have multiple food allergies, you can combine two into a food category such as tree nuts, shellfish, or citrus. Because you’re used to being careful with your diet, you have a +(IE) bonus to Intelligence (Investigation) checks to detect your stimulus or similar foods.
• Venom Allergy. You react more strongly to even mild venoms, whether from stings, bites, thorns, or other injected toxins. A venom allergy will automatically be a category based on type, such as insects, reptiles, or plants.
• Airborne Allergy. You are allergic to an inhaled substance, such as mold spores, animal dander, pollen, or certain gasses.
• Contact Allergy. You are allergic to a material, either liquid or solid, such a plant resin, iron, tannin (and thus leather), or wool. Because you’re used to being careful with materials, you have a +(IE) bonus to Intelligence (Investigation) checks to detect your stimulus or related materials.

Reactions vary depending on the contact nature and IE of the allergy as follows. If the reaction is a trait or complication, it is experienced at the IE of the allergy. If the stimulus is part of an ability or attack that requires a saving throw, you have a −(IE) penalty on the saving throw against that attack. A successful CR 8 + (IE) Wisdom (Medicine) check will reduce the duration by half.

Real-world Examples

Allergies, Food Intolerance, Celiac Disease, Mast Cell Activation Syndrome

Assistive Options

The best way to manage an allergy is to avoid the triggering substance. If this is not possible, flushing your skin or sinuses with water for a minute will reduce the IE by 1 for 1d20 minutes after the flushing. For food allergies, vomiting may reduce the duration as it removes the stimulus from your system.

You gain weight unrelated to diet and exercise. After every adventure or major campaign arc, you must succeed on a DC 8 + (IE) Constitution saving throw. On failure, your weight has increased by IE × 2d6 percent. On success, your weight has decreased by IE × 1d4 percent. For every fifty percent increase, you have a −1 penalty on Dexterity (Acrobatics) and Strength (Athletics) checks. For every ten percent decrease, you experience Temperature Sensitivity for 3d20 days as your body acclimates itself and must succeed on a DC 8 + (IE) Constitution saving throw or experience Fatigue until you succeed on the saving throw, which you can attempt daily after a long rest. You have a +(IE) bonus to Strength (Athletics) checks for swimming.

Real-world Examples

Hypothyroidism, Depression, Insomnia, Menopause, Cushing’s Disease, Polycystic Ovarian Syndrome, Congestive Heart Failure, Sleep Apnea, Edema, Diabetes, Down Syndrome

Assistive Options

Because this gain is unrelated to diet and exercise, little can be done besides acceptance.

You feel dizzy, lightheaded, and nauseated, unable to easily orient yourself in space. You have a −(IE) penalty on all Dexterity checks and saving throws, including initiative and Dexterity-based attack rolls, until you take a short rest. You feel Nausea and will vomit if you fail a DC 8 + (IE) Constitution saving throw, which will leave you incapacitated for 1d4 rounds. If this is a triggered trait, quick movement and stress are common causes.

Real-world Examples

Benign Paroxysmal Positional Vertigo, Vestibular Neuronitis, Meniere’s Disease, Labyrinthitis, Perilymph Fistula, Superior Semicircular Canal Dehiscence Syndrome

Assistive Options

Depending on the cause of the vertigo, certain specialized exercises or rest can help. For some, reducing salt, caffeine, and alcohol helps. Talk to your GM about whether yours can be managed and by what means.

You are sensitive to atmospheric temperature changes and have a small range of temperatures where you are comfortable, feeling like the environment is much warmer or colder than the actual temperature, or sweating or shivering when most people are comfortable. This range may change suddenly. You have a −(IE) penalty on Wisdom (Perception) checks to determine the relative environmental temperature.

Real-world Examples

Anxiety, Menopause

Assistive Options

Cloths soaked in warm or cold water can help you feel more comfortable but do not reduce the penalty.

Magical Assistance

Items that grant resistance to fire or cold can reduce the IE by 2 as applicable, but when your sensitivity fluctuates the other direction, it increases the IE by 1.