Dominaria introduced Merfolk Trickster, which causes a creature to lose all abilities, without setting a power and toughness.
What happens if a card such as Tarmogoyf loses all abilities?
Would Tarmagoyf become a 0/0 in this case, because a number not defined is treated as 0? Or would it possibly be a 0/1, because the printed toughness on the card is "*+1", and only the "
*" part is undefined? What about a card like Boneyard Wurm, would it just become 0/0 (and thus die)?
There seems to be a possible contradiction between the comprehensive rules and the Gatherer rulings. The Gatherer rulings say:
If the target creature has power and toughness written as / with an ability that defines its power and toughness, it’s 0/0 when it loses all abilities. If its power and toughness are written as */*+1, it’s 0/1, and so on.
Rule 208.5 deals with this situation:
208.5. If a creature somehow has no value for its power, its power is 0. The same is true for toughness.
It seems to me that a Tarmagoyf that loses all abilities has no toughness defined. It's toughness is written as "*/1+*", which according to 208.2, its toughness should be defined by its abilities.
So, while it is clear that a */* creature will be a 0/0 if it loses all abilities; what happens to a */*+1? Is it 0/0 or 0/1?
Also, I find it interesting, though not likely relevant, that Tarmogoyf is written "*/1+*" (with the 1 first), while the Gatherer ruling references cards that are "*/*+1" (with the * first).