What is the difference between gambling (qimar) and maysir?

Scholars have differed regarding the distinction between qimar (gambling) and maysir (games of chance). Some consider qimar to be more general than maysir, while others equate them. Their legal ruling is the same: prohibition, based on the Almighty's saying: (O YOU WHO HAVE BELIEVED, INDEED, INTOXICANTS, GAMBLING [AL-MAYSIR], IDOLATROUS SACRIFICES [AL-ANSAB], AND DIVINING ARROWS [AL-AZLAM] ARE BUT DEFILEMENT FROM THE WORK OF SATAN, SO AVOID IT THAT YOU MAY SUCCEED). And in the Hadith: "Whoever says to his companion: 'Come, let me gamble with you,' let him give charity."