I posted the same question on Quora and got the answer:
"the Kuru prince, surrounded by thecowherds, began to # sport and wander
cheerfully. And the citizens also and the soldiers by thousands began to sport, as best pleased them, in those woods, like the celestials. And the
herdsmen, well skilled in singing and dancing and instrumental music, and virgins decked in ornaments, began to minister to the pleasures of
Dhritarashtra's son. And the king surrounded by the ladies of the royal household began cheerfully to distribute wealth and food and # drinks_of_various_kinds amongst those that sought to please him, according to their desires (this passage clearly mentions they were drunk )
Duryodhana and others were making merriment there, they were celebrating a party. Duryodhana, surrounded by the Kuru ladies, distributed
wealth, food and various types of drinks among his followers (i.e. Karna, Sakuni, and other Kuru princes).
Duryodhana and others were celebrating a party there, so it is obvious that the drinks that they were taking was not water or milk. [Lol... were
Karna and Duryodhana children that they would
drink milk in a party?]
Karna, Duryodhana and others were drinking
wine .
"And the king, attended by # all_his_followers , began also to slay hyenas and buffaloes and deer and gayals and bears and boars all around.
And the king, piercing by his shafts those animals by thousands in deep forest, caused the deer to be caught in the more delightful parts of
the woods. Drinking # milk and # enjoying, O Bharata, various other delicious articles and beholding, as he proceeded, many delightful
forests and woods swarming with bees inebriate with floral honey and resounding with the notes of the peacock, the king at last reached the
sacred lake of Dwaitavana."
Vana Parva: Ghosha-yatra Parva: Section CCXXXVIII
Here it is written that Duryodhana, along with all
his followers (including Karna, Sakuni and
others) were enjoying and drinking milk. This is
complete insanity to think that Kauravas were
celebrating a party by drinking milk. Obviously
they drank some kind of wine (made from milk
and other objects).
Conclusion:- Karna and others were drinking wine, obviously they were partially (if not ompletely) drunk during their encounter with the
Gandharvas. This contributed greatly to their defeat in the battle against the Gandharvas.
why Karna fled where Arjuna succeeded against Gandharvas in full detail :
"when the Gandharvas were so commanded by
Chitrasena, they rushed weapons in hand,
towards the Dhritarashtra ranks. And beholding
the Gandharvas impetuously rushing towards
them with upraised weapons, the Kuru warriors
precipitously fled in all directions at the very
sight of Duryodhana."
Point-1: The war started here.
Point-2: The whole of the Kuru army fled
(including Duryodhana, his 100 brothers and
Sakuni), seeing the Gandharvas rushing towards
them with various weapons.
"And beholding the Kuru
soldiers all flying from the field with their backs
to the foe, the heroic Radheya alone fled not."
Point: The whole of the Kuru army fled, only
Karna remained on the battlefield.
"And seeing the mighty host of the Gandharvas
rushing towards him, Radheya checked them by
a perfect shower of arrows. And the Suta's son,
owing to his extreme lightness of hand, struck
hundreds of Gandharvas with Kshurapras and
arrows and Bhallas and various weapons made
of bones and steel. And that mighty warrior,
causing the heads of numerous Gandharvas to
roll down within a short time, made the ranks of
Chitrasena to yell in anguish."
Point-1: Karna alone checked the whole force of
the Gandharvas, and within a short span of time,
he slew hundreds of Gandharvas.
Point-2: While fighting with the Gandharvas,
Karna effectively used various types of arrows
and various types of other weapons. And while
using those weapons, he displayed his extreme
lightness of hand.
Point-3: Karna alone checked and overwhelmed
the vast Gandharva host.
"And although they were slaughtered in great numbers by Karna
endued with great intelligence, yet the
Gandharvas returned to the charge by hundreds
and thousands. And in consequence of the
swarms of Chitrasena's warriors rushing
impetuously to the field the earth itself became
soon covered by the Gandharva host."
Point-1: Karna slew a very large number of
Gandharvas.
Point-2: In spite of Karna's continuous onslaught,
the Gandharvas continued to rush towards him in
great numbers.
Point-3: The Gandharva army was much larger
than the Kuru army. The Gandharvas were so
many in number that the earth seemed to be
filled with the Gandharvas. Karna alone
withstood that vast force.
"Then king Duryodhana, and Sakuni, the son of Suvala, and
Dussasana, and Vikarna, and other sons of
Dhritarashtra, seated on cars the clatter of
whose wheels resembled the roars of Garuda,
returned to the charge, following the lead of
Karna, and began to slaughter that host. And
desirous of supporting Karna, these princes
invested the Gandharva army, with a large
number of cars and a strong body of horses.
Then the whole of the Gandharva host began to
fight with the Kauravas. And the encounter that
took place between the contending hosts was
fierce in the extreme and might make one's hair
stand on end."
Point-1: When Duryodhana beheld that Karna
alone had checked the vast Gandharva force, he
returned to the battlefield, along with his
brothers and the Kuru army.
Point-2: Karna thus got a strong back-up, and
continued to fight.
Point-3: A general war commenced between the
Kuru army and the huge Gandharva host.
"The Gandharvas, at last, afflicted
with the shafts of the Kuru army, seemed to be
exhausted. And the Kauravas beholding the
Gandharvas so afflicted sent up a loud sound."
Point-1: In the general engagement, the Kuru
army led by Karna completely overwhelmed the
Gandharvas.
Point-2: At this point of the battle, the
Gandharvas were nearly exhausted, and were on
the verge of defeat.
"And seeing the Gandharva host yielding to fear,
the angry Chitrasena sprang from his seat,
resolved to exterminate the Kuru army. And
conversant with various modes of warfare, he
waged on the fight, aided by his weapons of
illusion."
Point-1: When Karna, supported by the Kuru
army, had nearly vanquished the Gandharvas,
and the Gandharvas were struck with fear,
Chitrasena (king of the Gandharvas) entered the
battlefield.
Point-2: Chitrasena didn't engage in a duel/single
combat with Karna (or any other Kuru warrior).
And, he used neither any ordinary weapon nor
any celestial weapon against the Kuru army. He
directly used an illusion against the Kuru army.
He knew that he wouldn't be able to defeat
Karna in a single combat. He also knew that if
he had used any weapon (be it ordinary or
celestial), Karna would have baffled it with ease.
So he directly used an illusion.
Point-3: Chitrasena was a Gandharva.
Gandharvas possessed illusionary powers, and
were well-acquainted with illusions (and
illusionary warfare). But Karna and others in the
Kuru army were humans, who didn't possess
illusionary powers. According to the rules of war,
a warrior/warriors possessed of illusionary
powers should not use illusions against him/
those who doesn't/don't possess illusionary
powers, and if he/they does/do so, that is
considered as 'deceit' and 'violation of rules of
war'. Chitrasena used illusions against Karna and
the Kuru army (who were humans), and thus
violated the rules of war.
Note-1: Some people may ask where I have
found that using illusions against those who
didn't possess illusionary powers is a violation of
the rules of war. I would suggest them to read
the narratives of the duel between Abhimanyu
and Alamvusha on the 9th day and the duel
between Karna and Ghatotkacha on the 14th
night. In these duels Alamvusha and Ghatotkacha
(both of whom were Rakshasas, and possessed
of illusionary powers) used illusions against
Abhimanyu and Karna (both of whom were
humans, not possessing illusionary powers)
respectively and both of those Rakshasas were
marked as 'deceitful' for their acts (i.e. using
illusions against human warriors).
Note-2: If a warrior possessed of illusionary
powers use illusions against another warrior
possessed of illusionary powers, then that's not a
violation of the rules of war. (In case of
Rakshasa vs Rakshasa, Naga vs Naga,
Gandharva vs Gandharva, Naga vs Rakshasa,
Gandharva vs Rakshasa etc. scenarios)
"And the Kaurava warriors were then all
deprived of their senses by the illusion of
Chitrasena. And then, O Bharata, it seemed that
every warrior of the Kuru army was fallen upon
and surrounded by ten Gandharvas. And attacked
with great vigour, the Kuru host was greatly
afflicted and struck with panic. O king, all of
them that liked to live, fled from the field."
Point-1: In consequence of Chitrasena's sudden
illusionary attack, all Kuru warriors (including
Karna) were deprived of their senses. Karna and
others were nearly unconscious.
Point-2: Beholding the Kuru warriors (including
Karna) almost unconscious owing to the terrible
illusion of Chitrasena, the nearly defeated
Gandharvas attacked them with greater vigour.
This was another violation of the rules of war,
because attacking (or striking) unconscious
warriors was against the rules of war, but the
Gandharvas violated this rule also.
Point-3: Being thus attacked, large part of the
Kuru army fled from the battlefield. Only Karna,
Duryodhana, Duryodhana's brothers, Sakuni, and
a smaller portion of the Kuru army remained on
the battlefield.
"But while the entire Dhritarashtra host broke and
fled, Karna, that offspring of the Sun, stood there, O king,
immovable as a hill. Indeed, Duryodhana and
Karna and Sakuni, the son of Suvala, all fought
with the Gandharvas, although every one of them
was much wounded and mangled in the
encounter."
Point-1: As Karna and few other Kuru warriors
(who remained in the battlefield) were almost
unconscious, the Gandharvas used the
opportunity to mangle and wound them badly.
Point-2: Though nearly unconscious and
exceedingly wounded, yet Karna stayed on the
battlefield, and fought to the utmost of his
power.
Point-3: Karna lost his back-up force, as all of
them were almost unconscious, practically
useless.
At this point, let me clear some doubts that
often arise.
Doubt-1: Why did Karna fail to counter
Chitrasena's illusion?
Answer: Chitrasena used the illusion suddenly. At
first he wasn't in the battlefield. When Karna had
nearly defeated the Gandharvas, he suddenly
entered the battlefield and just after entering,
used a terrible illusion to make Karna and others
unconscious. Chitrasena did it without any
warning or challenge. He used deceit to defeat
Karna and others. Also people may question why Karna didn't use
any celestial weapon to counter the illusion (as
though he was nearly unconscious, yet he wasn't
completely senseless). The answer is Karna was
already drunk (though not completely, but he
drank wine just before the war, so it is obvious
that he was partially drunk), and when Chitrasena
used illusion, he became almost unconscious,
and in that condition, it wasn't possible to invoke
into existence celestial weapons as in order to
shoot celestial weapons complete concentration
is required (and it is completely foolishness to
expect that a drunk and almost unconscious
warrior could have complete concentration).
So, this is the reason why Karna had failed to
counter Chitrasena's illusion.
Doubt-2: Karna possessed his impenetrable
armour and ear-rings during Gandharva War.
Then how was he defeated?
Answer: Karna's armour and ear-rings had made
him immortal/unslayable, but it hadn't made him
invincible/undefeatable. Karna's armour and ear-
rings used to protect him from mortal/lethal/
deadly threats only, not from defeat.
Doubt-3: How did the Gandharvas manage to
mangle Karna exceedingly as Karna possessed
his impenetrable armour at that time?
Answer: Karna was exceedingly mangled, but it
is not mentioned in which parts of the body he
was mangled. So, it can be assumed that the
Gandharvas mangled those parts of Karna's body
which were not covered by his armour (forehead,
neck, hands, thighs etc.).
Karna also used the same technique to mangle
Abhimanyu on the 13th day of the Kurukshetra
War, when the latter was encased in an
impenetrable armour.
Doubt-4: Karna failed to counter Chitrasena's
illusion, so was he a poor warrior?
Answer: No, not at all. Karna failed to counter
Chitrasena's illusion owing to some specific
factors (Karna's being drunk, his being almost
unconscious, use of deceit by Chitrasena). But
when Karna fought with the same Gandharvas
during his digvijay, he successfully countered
their illusions and defeated them easily. Also
Karna successfully countered hundreds of terrible
illusions created by Rakshasa Ghatotkacha.
"All the Gandharvas then, desirous of
slaying Karna, rushed together by hundreds and
thousands towards Karna. And those mighty
warriors, desirous of slaying the Suta's son,
surrounded him on all sides, with swords and
battle-axes and spears. And some cut down the
yoke of his car, and some his flagstaff, and
some the shaft of his car, and some his horses,
and some his charioteer. And some cut down his
umbrella and some the wooden fender round his
car and some the joints of his car. It was thus
that many thousands of Gandharvas, together
attacking his car, broke it into minute
fragments."
Point-1: Though Karna was almost unconscious
and exceedingly wounded, yet he continued to
fight with the Gandharvas, slaying many of them.
Point-2: Considering Karna as their main threat,
the Gandharvas concentrated their attack on
Karna.
Point-3: Many thousands of Gandharvas, armed
with various kinds of weapons, together attacked
on Karna's chariot.
Point-4: An exceedingly wounded, almost
unconscious and intoxicated Karna failed to
counter this fierce group attack.
Point-5: Karna was not using his celestial Vijaya
bow and his celestial chariot during this war. He
was using an ordinary bow and an ordinary
chariot at that time. Some Gandharvas cut off
Karna's bow, some slew his horses, some slew
his charioteer, some cut down his standard,
some cut down his umbrella, some cut down his
flagstaff, some cut off the yoke of his chariot,
some cut off the shaft of his chariot, some cut
off the wooden fender around it, and some cut
off the joints of it. This was the most ferocious
and brutal group attack in the whole
Mahabharata.
The original answer was posted at http://www.quora.com/Why-did-Karna-fled-from-battle-with-Chitrasena-Gandharvas
