Doomsday Defense
The survival codex
Know how to survive. Know how to rebuild.
A free, searchable library of survival knowledge: short field notes you can read in a minute, and the full text of public-domain manuals and books on first aid, food, water, shelter, defense and rebuilding civilization.
- 22 field notes
- 19 books & manuals
- 264 chapters of full text
Critical knowledge: read these first
All field notes →-
Disinfecting Water with Household Bleach
8 drops of plain 5–9% bleach per gallon of clear water, stir, wait 30 minutes. Double it for cloudy or very cold water. The CDC table and the rules.
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Generators, Grills and Carbon Monoxide: The Outage Killer
Run generators outside, 20+ feet from doors, windows and vents. Never use generators, grills or camp heaters indoors. CO can kill people in their sleep.
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Heat Stroke vs. Heat Exhaustion: Know the Difference
Heavy sweating and clammy skin mean heat exhaustion: cool down. Hot red skin, 103°F+ and confusion mean heat stroke: a 911 emergency.
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Home Canning Safety: The Botulism Rules You Can't Break
Low-acid foods (vegetables, meat, fish) must be pressure-canned. Follow tested USDA times, and when in doubt, throw it out. Botulism kills.
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How to Boil Water to Make It Safe to Drink
Boiling is the most reliable way to kill germs in water. Bring clear water to a rolling boil for 1 minute, or 3 minutes above 6,500 feet.
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Lost? STOP: Stop, Think, Observe, Plan
The moment you realize you're lost, stop moving. Think, observe and plan. Staying put and making yourself visible usually gets you found faster.
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Nuclear Detonation: Get Inside, Stay Inside, Stay Tuned
After a nuclear blast you may have 10+ minutes before fallout arrives. Get deep inside a building, stay at least 24 hours, and listen for instructions.
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Recognizing and Treating Hypothermia
Shivering, confusion, fumbling hands and slurred speech mean the body is losing heat faster than it makes it. It can happen above 40°F if you're wet.
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Snakebite First Aid: What to Do and What Not to Do
Get to antivenom fast, keep the bite still and clean, and mark the swelling. No tourniquet, no cutting, no sucking, no ice. The old methods hurt.
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Stopping Severe Bleeding: Pressure, Packing, Tourniquet
A person can bleed to death in minutes. Firm direct pressure, packing deep wounds, and a tourniquet 2–3 inches above a limb wound save lives.
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The Four Rules of Firearm Safety
Treat every weapon as loaded. Never point it at anything you won't shoot. Finger off the trigger. Keep it on safe until you intend to fire.
Browse by topic
Full topic index →-
Survival Basics 3 entries
Where to start: survival priorities, the mindset that keeps people alive, and building kits for home, car and bug-out.
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Water 4 entries
You can last only about three days without water. Finding it, making it safe to drink, and storing enough for a crisis.
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Food 13 entries
Gathering, hunting, trapping, fishing, preserving and cooking food when stores are empty and the power is out.
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Shelter, Fire & Bushcraft 9 entries
Staying warm, dry and capable in the wild: shelters, fire craft, knots and cordage, edged tools and camping skills.
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Field Medicine 8 entries
First aid and austere medicine when help is far away: bleeding control, wounds, fractures, cold and heat injuries, illness.
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Navigation & Signals 3 entries
Finding your way without GPS, signaling rescuers, and communicating when cell networks are down.
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Security & Defense 3 entries
Protecting yourself, your family and your home: firearm safety and marksmanship, home security and operational security.
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Disaster Scenarios 10 entries
What to do in specific emergencies: nuclear attack, pandemic, grid-down, civil unrest, war and natural disasters.
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Rebuilding Civilization 10 entries
The long game: growing food, raising animals, keeping bees, and the crafts (smithing, tanning, soap) that rebuild a community.
From the library
All books & manuals →-
Canning, Freezing, Storing Garden Produce
USDA's guide to preserving a harvest: canning, freezing, drying, pickling, jams, root-cellar storage and community canneries (1977).
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Forge Work
A 1912 manual-training course in blacksmithing: forge tools, drawing, upsetting and welding, tempering tool steel, and making tools.
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Pistol Marksmanship (MCRP 3-01B)
The Marine Corps pistol manual: weapons handling and safety, marksmanship fundamentals, grip and positions, cover, and low-light shooting.
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Shelters, Shacks and Shanties
Dan Beard's illustrated 1914 guide to building shelters with just a hatchet or an axe, from lean-tos and bark huts to log cabins.
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The Book of Camp-Lore and Woodcraft
Dan Beard's 1920 handbook on fire by friction and flint, cooking fires, camp kitchens, packing horses and dogs, and axe and saw work.
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Woodcraft
Nessmuk's classic 1884 pocket guide to traveling light in the woods: camps, campfires, cooking, and getting lost and found again.
Recently added
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Building a Basic Disaster Supplies Kit
FEMA's core kit: water, food, radio, flashlight, first aid, batteries, whistle, mask, plastic sheeting and tape, tools, maps and a charged phone.
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Disinfecting Water with Household Bleach
8 drops of plain 5–9% bleach per gallon of clear water, stir, wait 30 minutes. Double it for cloudy or very cold water. The CDC table and the rules.
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Frostbite: Signs and First Aid
Redness or pain, then white or grayish-yellow, firm or waxy, numb skin. Rewarm in warm (not hot) water, and never rub it or use direct heat.
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FRS and GMRS Radios: Talking When Cell Networks Fail
FRS walkie-talkies need no license; GMRS radios share the channels but allow more power and repeaters, with an FCC license. Plus NOAA weather radio.
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Generators, Grills and Carbon Monoxide: The Outage Killer
Run generators outside, 20+ feet from doors, windows and vents. Never use generators, grills or camp heaters indoors. CO can kill people in their sleep.
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Haybox Cooking: Retained-Heat Cooking That Saves Fuel
Boil a pot, then seal it in an insulated box and let stored heat finish the cooking over hours. Cuts fuel use dramatically when fuel is scarce.