Gambling, as any sound minded person will tell you, is a great evil of the society and immensely harmful to the wellbeing of the human social order. As such, Islam has categorically and firmly prohibited all forms of gambling, so that the human society is saved from its ill-effects and harms.
Allah Most High says: O you who believe! Intoxicants and gambling, (dedication of) stones and (divination by) arrows, are an abomination of Satan's handwork: Abstain from such (abomination), that you may prosper. Satan's plan is (but) to excite enmity and hatred between you with intoxicants and gambling, and hinder you from the remembrance of Allah, and from prayer: Will you not then abstain? (Surah al-Maidah, V. 90-91)
In the above verse of the Quran, the term al-Maysir has been used in order to describe gambling, whilst in some other texts of the Sunnah, we find the word al-Qimar being used. The meaning of both these terms and expressions is the same. Sayyiduna Abd Allah ibn Umar (Allah be pleased with him) says:
al-Maysir is the al-Qimar. The same has been narrated from Mujahid, Said ibn al-Musayyib, Hasan al-Basri, Muhammad ibn Sirin, Ata ibn Abi Rabah and others (may Allah be pleased with them all). (See: Tafisr Ibn Jarir, 2/358)
The Messenger of Allah (Allah bless him & give him peace) emphasized the prohibition of gambling to such an extent that even considering to take part in gambling was regarded to be blameworthy.
Sayyiduna Abu Hurayra (Allah be pleased with him) narrates that the Messenger of Allah (Allah bless him & give him peace) said: Whosoever says to another: come lets gamble should give in charity (m: as a form of expiation for intending to gamble). (Sahih al-Bukhari, no. 4579)
Imam Abu Bakr al-Jassas (Allah have mercy on him) states:
There is no difference of opinion between the scholars regarding the prohibition of gambling. (Ahkam al-Quran, 1/329)