-Wolverine does not have adamantium
-Wolverine is unarmed, Cap has his shield.
-Morals are on. Let's say that both of them have been led to believe that the other has 'turned to the dark side'. No amount of banter during the fight will let either one realize that they're still on the same side.
-Standard rules for victory apply (KO, death, incapacitation, ect).
-Fight takes place in the middle of the street in Manhattan at dusk, unpopulated. There are still cars around though.
-Fighters start 50 yards apart, within sight of each other.
If you have any discrepancies about these rules (you think I gave one character too much of an advantage) let me know.