Day to day - wallet, phone, keys
As proper edc - knife, light, firestarter (for me usually a Fenix EO1, a small sak (with a stockman or similar whenever possible) and a bic lighter)

Multi-tool.
Small L.E.D. Light.
Lighter.


Multi-tool because a decent quality one has much capability than a simple knife.

Pretty much all of America will carry the folllowing three items in some form:
1) key or keys (car, home, whatever)
2) money
3) ID

Only an ultralight hiker might choose to ditch the keys, but 2 and 3 are highly recommended.

So once we get past that, the next three depend on where I am:

When I'm around home:
1) Cell phone
2) Flashlight
3) Multitool

When I'm "out there":
1) Flashlight
2) Multitool (oh I have so many now)
3) DR designed PSK Check out those great reviews!

When I'm on a plane:
1) Cell phone
2) Flashlight
3) Crappy Swisskey

I actually always have the crappy swisskey on me because its on my keychain, but, if I could only pick 3 it would not be on the first 2 lists.

It should be noted that I am assuming that any reasonable person will be carrying your ID and some money in a useful form no matter what/where they are going.

Besides wallet & keys, when I leave the house I have the following for pocket carry:
- Locking folder (Benchmade 940 or RSK Mk1)
- Mission Wallet (contains 1xAAA LED light, SAK Farmer, Leatherman Squirt E4, Ferro rod and other small odds and ends).

The three most used items are the BM 940, the LED light and the LM Squirt E4, so those would be my pick for three.

Edit to note that the BM 940 and Mission Wallet are on/in my pockets before I grab the wallet and keys.

1.) One of my many Swiss Army Knives.
2.) A bandanda in my back pocket.
3.) A firesteel clipped to the keyring of the SAK...

1)A working brain with skills, knowledge, insight, and judgment to improvise, adapt and overcome the challenges faced each day.
2)A will to keep trying and never quit
3)Leatherman Wave

1) Victorinox Signiture Classic knife
2) Small generic, but bright, LED key chain light
3) Modified (shortend) REI key chain whistle

All fit together on a small 1/4 keyring in the coin pocket of any pair of jeans. If I'm going anywhere, then I add the wallet, keys, phone, etc.

Do you mean to include appropriate outerwear and footwear? I'll assume not.

I don't go anywhere without a knife (most often a Ritter miniGrip), iPhone, and flashlight (normally a Quark 123 R5).

1) means to make fire
2) a knife
3) a light

-john

Pocket knife, paracord and water-proof matches.

They are the three most difficult things to produce in a survival situation, and with them you can build shelter and other things to help you survive.