The Blood Bank
Every character is born with a blood type, and it matters.
🧬 Blood types
Eight types, distributed realistically across your population:
| Type | Share of players |
|---|---|
| O+ | 38% |
| A+ | 34% |
| B+ | 9% |
| O− | 7% |
| A− | 6% |
| AB+ | 3% |
| B− | 2% |
| AB− | 1% |
A character's blood type is unknown until a blood test reveals it. Once known, it is stored in their medical profile forever.
✅ Compatibility
| Recipient | Can receive from |
|---|---|
| O− | O− only |
| O+ | O−, O+ |
| A− | O−, A− |
| A+ | O−, O+, A−, A+ |
| B− | O−, B− |
| B+ | O−, O+, B−, B+ |
| AB− | O−, A−, B−, AB− |
| AB+ | Everything |
O− is the universal donor. AB+ is the universal recipient. That is why O− donors are the most valuable people on your server.
☠️ Getting it wrong
An incompatible transfusion is a catastrophe:
| Heart rate | +40 |
| Systolic pressure | −35 |
| Temperature | +2.0 °C |
| Blood volume | −400 ml, they lose more than they gained |
| Death chance | 15% |
Survivors get the Transfusion Reaction disease, high fever, low blood pressure, shaking, cured with antihistamine or epinephrine.
Run a blood test before you transfuse. Guessing has a one in seven chance of killing your patient outright.
💉 Transfusing
- Get a
blood_bagfrom the hospital's Blood Fridge. - Check the bag's type against the patient's.
- Give it. +500 ml blood volume.
A transfusion goes through an IV line, if the patient doesn't have one yet, you place it first. A downed patient can get an IO line instead. See Surgery & Procedures → IV access.
Bags expire after 14 days.
🏷️ The bag label
Every bag carries a printed label. Use the bag to read it:
| Unit number | Its own number, like U26-04821, with a barcode |
| Blood group | Only once the bag is typed |
| Donor | The donor's initials, never a name. Shop bags say Blood bank |
| Collected / Expires | The dates |
An untyped bag is stamped Untyped - do not use, and an out-of-date one Expired.
In Patient Care, each bag in the transfusion list shows its unit number and expiry, so you hang the bag you meant to.
🎁 Donations
At a hospital's Blood Donation Chair, any player can donate.
| Amount | 500 ml |
| Reward | $250 |
| Cooldown | 2 hours |
| Takes | 15 seconds |
A medic runs the donation at the chair. The bag goes into the medic's inventory, untyped, the label carries the donor's initials but no blood group.
Before it can be given to anyone, type it at the Laboratory → Type Blood Bags. That types every untyped bag you carry at once.
Medics earn 10 XP for processing a donation.
🛒 Shop bags
For servers that cannot rely on player donations, the blood fridge can also sell universal O− bags for $400 (rank 1+).
Turn this off (shopBags.enabled = false) if you want a donation-driven economy where running out of blood is a real event.
🩸 Blood volume vs blood cells
| Method | Restores |
|---|---|
| Saline IV (500 ml) | +350 ml volume |
| Saline IV (250 ml) | +175 ml volume |
| Electrolyte drink | +50 ml |
| Blood bag | +500 ml |
| Natural regeneration | 3 ml per tick, only when not bleeding |
Saline buys time. Blood fixes the problem. For a patient who bled out, PEA will not convert to a pulse without real volume.
📊 Reference
| Maximum blood volume | 5,000 ml |
| Collapse into last stand | below 2,600 ml |
| Death while down | below 1,500 ml |
| Minimum for a revive to hold | 3,000 ml |