Is it lawful to divorce your wife three times at once according to islam or sharia?
No it's unlawful. There're three types of divorces, Talaq Ahsan, Talaq Hassan and Talaq Biddat. Three times divorce is called Talaq Biddat which is not the Islamic way and Prophet Muhammad forbade it in his life.
No , Three ,four etc at one time is considered as Talaq 1 , but remember the terms and conditions of Nikkah must be applied at the time of Talaq , e.g 4 Gawah are must at the time of Talaq.
it is unlawful but if you give three divorces at a time they do count three according to Ahadith of Sunan Tirmzi and Sunan Abi Dawood
No, Terms and conditions of Talaq are same as Nikkah .Talaq is not a ping pong game.It is a very much serious matter.At a time three talaq words are nothing but a gup shup of Sectarian Mullahs. Abu Hayyan Aadil Saeed Al Zaidi Al Hashmi .