When a pokemon card says 20x the number of energy do you do 20 damage if there is no energy on a pokemon or would it be zero? Mewtwo for example, is it 20 plus the number of energies?
Let's say you talk about this Mewtwo : http://pokeplayer.com/cardex/next_destinies/98-mewtwo-ex
If Mewtwo has 2 energies and the Defending Pokémon has 0 energies, that would do 20 × 2 = 40 damage.
If for a weird reason you were able to use X Ball without having any energy attached, and 0 energies on the Defending Pokémon, that would do 20 × 0 = 0 damage.
Simple three-step process
- you must meet the energy requirements to make an attack
- calculate the damage based on the attack's text directions, which are often dependent on number of energies attached.
- apply the effects of any tool cards and weakness/resistance
e.g., the Mewtwo.
- you must have at least two energies attached to attack
- assuming you have two energies attached and your opponent has none, you deliver 40 damage, which is the minimum possible (at this step).
- your opponent has a choice helmet and is a fighting pokemon with 2x weakness to psychic. the damage is reduced by the tool card, but increased by its typing. you do the math.
There are two different kinds of damage modifiers common on Pokémon cards.
xmodifier. These do an amount times a multiplier, but have a zero 'base' attack damage. The MewTwo likely mentioned here does
20xdamage, which would have a zero base.
+modifier. Ultra Necrozma GX has an attack like this, Photon Geyser, which does 20 damage plus 80 more damage for every basic psychic energy card discarded. So if Ultra Necrozma had a Double Dragon energy attached, and no other energy, and used Photon Geyser, it would still do 20 damage.
Pokémon uses these symbols consistently on the cards. If there is an
x after the big damage number (printed on the same line as the attack name), then there will be a 0 base damage; if there is a
+ then there is that number plus additional damage mentioned in the card text (sometimes a multiplier, sometimes just a set amount).