Terseness only promotes communication if essential information is not left out.

Example 1: "In a Wicked Age"

QuoteConsulting the oracle
Someone choose an oracle. Your choices are Blood
& Sex, God-kings of War, the Unquiet Past, and
a Nest of Vipers. It doesn’t matter who chooses.
Someone shuffle the deck and deal four cards
where everyone can see.
Someone go to the oracle and read out its entries
for your four cards.
Suppose for example that you chose Blood &
Sex, and you dealt the king of diamonds, the 10 of
spades, the 10 of clubs, and the 9 of hearts. that’s
the desert horsemen hiding the woman, the spirit
of passion, the marriage of the girl to the stone
effigy, and the exorcist, severe.
One of you needs to be the GM. GM, don’t
choose, deal or read – have your friends do those.
You write. Copy the entries onto your story sheet.
All together, read the entries out into a list of
characters. (You write, and lead the reading.)
Read the explicit characters, and read the implied
characters too, and decide as you go and by your
gut what counts as a character. :cool:

A reasonable person can read between some of the lines.  What is going on is the setup akin to character generation.  What is missing is a very simple page reference.  If they had put "consult the table on page 29" anywhere in the above, the rules would be more readable and more useful.  The Oracle is a table printed on paper.  It is not a player, an NPC, or a special gaming aid sold at hobby stores.  

My guess is that the writer would have felt too unhip if he said, "Check the table on page 29."  So he tried to be vague and glamorous and he wrote explanatory text that does not explain.

Notice that the second person "You write" is much less clear than "The GM writes."  The writer knows damn well that the GM isn't the only one who reads the rules.

The conclusion mentions that the tables in question used to be called "plot elements."  I don't doubt that they produce some excellent plots that work well in-game.  Heck, I may even throw them into a GURPS game and see if they spice things up.  But I will call them "Plot Element Tables #1-4," at least when I write about them.

Moral: Terse, vague wording is for guilty criminals concealing their misdeeds, not for rule designers.

Example 2: "GURPS Characters 4th Edition"

QuoteCombat Paralysis
-15 points
You tend to "freeze up" in combat
situations, and receive -2 to all Fright
Checks. This has nothing to do with
Cowardice (p. 129) - you may be
brave, but your body betrays you.
In any situation in which personal
harm seems imminent, make a HT
roll. Do not roll until the instant you
need to fight, run, pull the trigger, or
whatever. Any roll over 13 is a failure,
even if you have HT 14+. On a success,
you can act normally. On a failure, you
are mentally stunned (see Effects of
Stun, p. 420). Make another HT roll
every second, at a cumulative +1 per
turn after the first, to break the freeze.
A quick slap from a friend gives +1 to
your cumulative roll.
Once you unfreeze, you will not
freeze again until the immediate dan-
ger is over. Then, in the next dangerous
situation, you may freeze once again.
This trait is the opposite of Combat
Reflexes (p. 43). You cannot have
both.

GURPS is not perfect, but at least it's well written enough to communicate its intended mechanics in a small amount of space.