about effects

[nosada]

lets say i have swalbu as my active with the attack :
:colorless Super Speed
Flip a coin, If heads, prevent all effects of an attack, including damage done to swalbu during your opponent's next turn

and i got piplup as defending pokemon with the attack :
:water::colorless Water Splash 20
Flip a coin. If heads, this attack does 20 damage plus 10 more damage

and my question is:
what does including damage refers to ? the 10 additional damage or the direct 20 damage hit ?

 

[Big Daddy Snorlax]

"Including damage" means it prevents all damage, both the base damage of 20 and the additional 10 damage you might add with the flip.

The wording is there because some attacks prevent effects but not damage. Please note that the additional 10 damage in this example is not an effect, it is damage. Something that prevented only effects would not stop the additional 10 if you got heads on the flip. "Placing damage counters" is an example of an effect.

BDS