finding invisible characters

[Mojo Jojo]

Couldnt you just ready an action to attack anyone attacking you?

 

[ForceUser]

Couldnt you just ready an action to attack anyone attacking you?

Sure, but you've got only a 1-in-8 chance (or worse if your invisible foe has reach!) of picking the right square to attack.

 

[Kershek]

I would think if someone attacked and hit you, that you would know the square from which it originated.

 

[Legildur]

DMG, p295 again, next paragraph down:

If an invisible creature strikes a character, the character struck still knows the location of the creature that struck him (until, of course, the invisible creature moves). The only exception is if the invisible creature has a reach greater than 5 feet. In this case, the struck character knows the general location of the creature but has not pinpointed the exact location.

 

[Mephistopheles]

...
The only exception is if the invisible creature has a reach greater than 5 feet.
...

Taken literally this implies that an invisible dragon (or any other creature with a reach greater than 5 feet) who is adjacent to you and whacks you is more difficult to pinpoint than an invisible human (or any other creature with a reach of only 5 feet) who is adjacent to you and whacks you. I guess they meant to say "The only exception is if the invisible creature has a reach greater than 5 feet and is not adjacent to you when it attacks you.". An obvious enough assumption for reasonable people, perhaps, but D&D players often go out of their way to be unreasonable people if it will provide some benefit.