Do you get full face value of losing lottery scratch off tickets as a tax write off?

That is considered gambling.

Gambling losses are deductible on Schedule A. So you can only claim the loss if you itemize deductions. BUT you can only claim losses up to the amount of your winnings. All gambling winnings must be listed on Form 1040. You will need proof of the losses if audited.

So, gambling losses can offset winnings. But they can not offset other income.