Is trading a player for real money in exchange for a key to open a loot box within the game considered haram, knowing that the contents of the box are known beforehand?

It is difficult to rule on issues related to the details of electronic games merely by description, as a ruling on something is an offshoot of its conception. Therefore, the answer to the question is general. The guidelines for electronic games were previously explained in Fatwa no. 98642.

The buying and selling of add-ons in games is a subsidiary of the ruling on the game itself. If the game is permissible, then it is permissible to exchange compensation for the additional features, provided that the item being sold is known. Loot boxes, the contents of which are known to contain benefits, may be bought and sold. However, if their contents are unknown, it is impermissible to purchase them due to gharar (excessive uncertainty), as stated in Fatwa no. 144092.