Name:Desperate Gambit
ManaCost:R
Types:Instant
A:SP$ ChooseSource | Cost$ R | Choices$ Card.YouCtrl | RememberChosen$ True | SubAbility$ CoinFlip | SpellDescription$ Choose a source you control and flip a coin. If you win the flip, the next time that source would deal damage this turn, it deals double that damage instead. If you lose the flip, the next time it would deal damage this turn, prevent that damage.
SVar:CoinFlip:DB$ FlipACoin | WinSubAbility$ CreateWinEffect | LoseSubAbility$ CreateLossEffect | ConditionDefined$ Remembered | ConditionPresent$ Card | ConditionCompare$ GE1
# Winning Effect
SVar:CreateWinEffect:DB$ Effect | Name$ Desperate Gambit Win Effect | ReplacementEffects$ EventWinDamageDone | SVars$ DmgTwice,WinX,ExileEffect | References$ EventWinDamageDone,DGDmgTimes2,WinX | RememberObjects$ Remembered
SVar:EventWinDamageDone:Event$ DamageDone | ValidSource$ Card.IsRemembered | ReplaceWith$ DmgTwice | Description$ The next time source would deal damage this turn, it deals double that damage instead.
SVar:DmgTwice:DB$ ReplaceEffect | VarName$ DamageAmount | VarValue$ WinX | References$ WinX | SubAbility$ ExileEffect
SVar:WinX:ReplaceCount$DamageAmount/Twice
# Losing Effect
SVar:CreateLossEffect:DB$ Effect | Name$ Desperate Gambit Loss Effect | ReplacementEffects$ EventLossDamageDone | SVars$ ExileEffect | References$ EventLossDamageDone,ExileEffect | RememberObjects$ Remembered
SVar:EventLossDamageDone:Event$ DamageDone | ValidSource$ Card.IsRemembered | ReplaceWith$ ExileEffect | PreventionEffect$ True | Description$ The next time it would deal damage this turn, prevent that damage.
SVar:ExileEffect:DB$ ChangeZone | Defined$ Self | Origin$ Command | Destination$ Exile
SVar:RemAIDeck:True
SVar:Picture:http://www.wizards.com/global/images/magic/general/desperate_gambit.jpg
Oracle:Choose a source you control and flip a coin. If you win the flip, the next time that source would deal damage this turn, it deals double that damage instead. If you lose the flip, the next time it would deal damage this turn, prevent that damage.