Why did Rama try to kill an innocent deer just for its skin?

Question

Hinduism doesn't favour violence or killing innocent beings. We support being vegetarians.

But isn't killing a deer for its golden skin unjustified?

I'm referring to the incident in Ramayana where Rama hunted the Golden Deer (Mareecha) for its skin. From here:

Rama eliminates Maareecha when he is escaping beyond reach in the form of Golden Deer. He sports with that deer for a long time and when it is leading him away and afar from the hermitage, he is vexed with the trickery of the deer and kills it.

Answer 1

We find one of the possible explanation of Shree Rama's act of Killing a deer who actually was a demon named Maricha, Sent by Ravana ,to take Shree Rama away from his hut ,and then to abduct Devi Sita in shreemad Bhgvatam.

So this was Ravanas evil plan.That deer wasn't actually a Innocent animal but a demon disguised as Golden Deer.

And act of killing of Demon Maricha or Ravana,just was one of the leelas of Shree Rama.

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तस्यापि भगवानेष साक्षाद ब्रह्मम्यो हरी:।
  अंशांशेन चतुर्धागात पुत्रत्वं प्रार्थित:सुरै:॥
  रामलक्ष्मणभरतशत्रुघ्ना इति संज्ञया॥2॥
 
tasyāpi bhagavān eṣa sākṣād brahmamayo hariḥ
  aṁśāṁśena caturdhāgāt putratvaṁ prārthitaḥ suraiḥ
  rāma-lakṣmaṇa-bharata-śatrughnā iti saṁjñayā 

  Meaning - Being prayed for by the demigods, the Supreme Personality of Godhead, the Absolute Truth Himself, directly appeared with His expansion and expansions of the expansion. Their holy names were Rāma, Lakṣmaṇa, Bharata and Śatrughna. These celebrated incarnations thus appeared in four forms as the sons of Mahārāja Daśaratha. SB 9.10.2

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सिताकथाश्रवणदीपितहॄच्छयेन ।
  सृष्टम् विलोक्य नृपते दशकन्धरेण।।
  जघ्नेsद्भुतैणवपूषाssश्रमतोsपकृष्ठो
  मारीचमाशु विशिखेन यथा कुमुग्र:॥10॥
 
sītā-kathā-śravaṇa-dīpita-hṛc-chayena
  sṛṣṭaṁ vilokya nṛpate daśa-kandhareṇa
jaghne ’dbhutaiṇa-vapuṣāśramato ’pakṛṣṭo
  mārīcam āśu viśikhena yathā kam ugraḥ
 

O King Parīkṣit, when Rāvaṇa, who had ten heads on his shoulders, heard about the beautiful and attractive features of Sītā, his mind was agitated by lusty desires, and he went to kidnap her. To distract Lord Rāmacandra from His āśrama, Rāvaṇa sent Mārīca in the form of a golden deer, and when Lord Rāmacandra saw that wonderful deer, He left His residence and followed it and finally killed it with a sharp arrow, just as Lord Śiva killed Dakṣa.SB 9.10.10

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So from description given in this chapter we can see that originally Ravanas intention was to abduct sita so he used power of Mayavi Demon Maricha to fulfil his evil plan.As no actual killing of innocent deer took place ,but at the end Golden Deer shown his original demon form while dying.

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This is further clarified in Valmiki Ramayana.

सौवर्णः त्वम् मृगो भूत्वा चित्रो रजत बिन्दुभिः || ३-४०-१७
आश्रमे तस्य रामस्य सीतायाः प्रमुखे चर |
प्रलोभयित्वा वैदेहीम् यथा इष्टम् गन्तुम् अर्हसि || ३-४०-१८

On becoming an amazing silver-potted golden deer you move in front of Seetha in the hermitage of Rama, and on verily alluring Vaidehi you can go away as you like. VR 3-40-17, 18

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प्राप्य सीताम् अयुद्धेन वंचयित्वा तु राघवम् |
लंकाम् प्रति गमिष्यामि कृत कार्यः सह त्वया || ३-४०-२५

"My goal will be achieved just by misleading Raghava, and by gaining Seetha without a conflict, then I will proceed to Lanka along with you. [3-40-25]

So the act of killing Golden deer by Shree Rama is completely justified one.As it was his leela or plan.
Read whole chapter Here

Answer 2

Rama was not trying to kill the golden deer for its skin. Sita wanted it as a pet to bring back to Ayodhya; here's what she tells Rama in this chapter of the Aranya Kanda of the Ramayana:

Oh, nobleman's son, that delightful deer is stealing my heart, oh, dextrous one, bring it round, it will be our plaything. Here in the threshold of our hermitage many animals with adorable manifestation are moving about in flocks and herds, say Caamara deer, like that Srimara deer. Also the animals that are excellent in their form, say monkeys, are moving here. Likewise herds of Kinnara deer, spotted-deer, and even bears of great-might are freely moving here. As to how this extraordinary deer is appearing, oh, king, by way of its brilliance, tameness, or by the lustre of its skin, I have not so far seen any coequal to this. Diversely coloured, amazingly limbed, and spotted with gemlike dapples it is shining forth like a deer that is completely gemmy, and while nonchalantly moving before me it is enlivening the forest like the moon. Ah, what a form, ah, what a brilliance, what a beautiful bleat! This amazingly limbed deer is wonderful, and this is stealing my heart, as it were. It will be surprising if this deer draws into your capture alive and well, as it creates astonishment to one and all. When we return to kingdom on completing our dwelling in forest this deer becomes a masterpiece in palacechambers for us. Oh, lord, the form of this deer creates an excellent jubilation to Bharata, to you the son of the nobleman, to my mothers in law, and also to me in palace chambers. Else if that best deer does not come into you capture while alive, oh tigerly man, at the least its gorgeous deerskin will be remnant of it... I wish to sit along with you on its golden deerskin, overlaying it on a seat of tender darbha grass blades, in case the deer is felled.

So as you can see, it's only if Rama accidentally kills it in the process of trying to capture it that Sita wants its skin. And in any case Kshatriyas are allowed to freely hunt animals, as Rama himself tells Vali in this chapter of the Kishkindha Kanda of the Ramayana:

In this world even the kingly sages well-versed in virtue will go on hunting, and hunting is no face to face game, as such, oh, vanara, therefore I felled you in combat with my arrow because you are a tree-branch animal, whether you are not combating with me or combating against me.

I discuss the justification for Rama killing Vali in more detail in my answer here.

Answer 3

Isn't killing a deer for its golden skin unjustified?

In Rāma's case, it's not unjustified. Revealing her second boon to Daśaratha, Kaikeyī says the following:

नव पञ्च च वर्षाणि दण्डकारण्यमाश्रितः || २-११-२६
चीराजिनजटाधारी रामो भवतु तापसः |

Rama has to take refuge in the forest of Dandaka for fourteen years and let him become an ascetic wearing rags, deer skin and matted hair.

चीरा (cīrā) means 'piece of cloth' and अजिन (ajina) means 'skin of a wild animal.'

So, clearly, in those days, when you live in a forest, that's your usual attire. Rāma was simply following the norms of his day. Hunting, meat-eating, using deerskin as a mat or as a coat to protect oneself from the weather was all normal for forest dwellers.

Also, from Bhagavad-gītā (Ch. 6: Dhyāna-yoga 11-12), we have:

To practice yoga, one should go to a secluded place and should lay kuśa grass on the ground and then cover it with a deerskin and a soft cloth. The seat should be neither too high nor too low and should be situated in a sacred place. The yogī should then sit on it very firmly and practice yoga to purify the heart by controlling his mind, senses and activities and fixing the mind on one point.

Now, one should not misinterpret the above to mean one cannot do yoga without getting a deerskin first, and ignoring other more important instructions.

In your comment, you also ask:

Where is it said that Kshatriyas are allowed to hunt in Vedas?

Stating his opinion in Anuśāsana-parva of the Mahābhārata, this is what Bhīṣma says:

It is even so, O mighty-armed one, as thou sayest. There is nothing on earth that is superior to flesh in point of taste. There is nothing that is more beneficial then flesh to persons that are lean, or weak, or afflicted with disease, or addicted to sexual congress or exhausted with travel. Flesh speedily increases strength. It produces great development. There is no food, O scorcher of foes, that is superior to flesh.

...

Hence, O Bharata, even royal sages betake themselves to the practice of hunting. By such conduct they do not become stained with sin. Indeed, the practice is not regarded as sinful.

In the earlier chapter, he says:

Many kings in ancient days, O son of Pritha, who had constituted themselves the souls of all creatures and who were conversant with the truths of all things, viz., Soul and Not-soul, had abstained from flesh either for the whole of the month of Karttika or for the whole of the lighted fortnight in that month. They were Nabhaga and Amvarisha and the high-souled Gaya and Ayu and Anaranya and Dilipa and Raghu and Puru and Kartavirya and Aniruddha and Nahusha and Yayati and Nrigas and Vishwaksena and Sasavindu and Yuvanaswa and Sivi, the son of Usinara, and Muchukunda and Mandhatri, and Harischandra. Do thou always speak the truth. Never speak an untruth. Truth is an eternal duty. It is by truth that Harischandra roves through heaven like a second Chandramas. These other kings also, viz., Syenachitra, O monarch, and Somaka and Vrika and Raivata and Rantideva and Vasu and Srinjaya, and Dushmanta and Karushma and Rama and Alarka and Nala, and Virupaswa and Nimi and Janaka of great intelligence, and Aila and Prithu and Virasena, and Ikshvaku, and Sambhu, and Sweta, and Sagara, and Aja and Dhundhu and Suvahu, and Haryaswa and Kshupa and Bharata, O monarch, did not eat flesh for the month of Karttika and as the consequence thereof attained to heaven...

When we see Rāma and Kṛṣṇa as kṣatriya kings & in light of above statements, their actions are justified.

Now Bhīṣma also says:

13,117.037a   ahiṃsā paramo dharmas tathāhiṃsā paro damaḥ
13,117.037c   ahiṃsā paramaṃ dānam ahiṃsā paramaṃ tapaḥ
13,117.038a   ahiṃsā paramo yajñas tathāhiṃsā paraṃ balam
13,117.038c   ahiṃsā paramaṃ mitram ahiṃsā paramaṃ sukham
13,117.038e   ahiṃsā paramaṃ satyam ahiṃsā paramaṃ śrutam

Abstention from cruelty is the highest Religion ... is the highest self-control.
Abstention from cruelty is the highest gift ... is the highest penance.
Abstention from cruelty is the highest sacrifice ... is the highest puissance.
Abstention from cruelty is the highest friend ... is the highest happiness.
Abstention from cruelty is the highest truth ... is the highest Sruti.

But that is only possible for sages:

13,116.073a   madhu māṃsaṃ ca ye nityaṃ varjayantīha dhārmikāḥ
13,116.073c   janmaprabhṛti madyaṃ ca sarve te munayaḥ smṛtāḥ

These righteous men who, from the time of birth, abstain from honey and meat and wine, are regarded as Munis.

In conclusion, we should avoid judging characters in Hindu scriptures based on current trends and also mixing duties and living styles of different varṇas (kṣatriyas, brāhmaṇas, etc.) or of sannyāsīs.