Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
As for your query, you should know that any game containing paying money under winning or losing is impermissible (haram).
In his response to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
Any game that involves payment of money on the basis of chance is not permissible in the Shari`ah. Poker, like any others, may or may not involve losing/gaining money. If it does not involve that and used just for entertainment at times that do not take over any prayer, work, study or doing any useful service, is not then forbidden (haram).