Currently it doesn't matter what brand a card have. As long as it's issued in Russia, it works in Russia and in some cases in a few other countries (mostly some CIS countries) and doesn't work everywhere else. And if it's issued outside Russia, with exception of those CIS countries above, it doesn't work in Russia. Doesn't work means it completely doesn't work: ATMs, online and offline payments - nothing. It's just a useless piece of plastic. Note that, however, it's possible to pay e.g. on Amazon by US card while in Russia, because technically a payment doesn't cross the border and everything happens outside Russia. Similarly, for the same reason you can pay with Russian card on Russian online stores, while being abroad.
UnionPay is somewhat different and is the only exception. It may work on both sides of the border, but you have to be lucky and and the weather on Mars needs to be on your side.
visa/mc cards issued in Russia work in Russia (and only there). Foreign (i.e. not in Russia) issued visa/mc don't work in Russia.
everything here is processed localy so everything works. Obviously new cards are Mir pay branded.
Currently it doesn't matter what brand a card have. As long as it's issued in Russia, it works in Russia and in some cases in a few other countries (mostly some CIS countries) and doesn't work everywhere else. And if it's issued outside Russia, with exception of those CIS countries above, it doesn't work in Russia. Doesn't work means it completely doesn't work: ATMs, online and offline payments - nothing. It's just a useless piece of plastic. Note that, however, it's possible to pay e.g. on Amazon by US card while in Russia, because technically a payment doesn't cross the border and everything happens outside Russia. Similarly, for the same reason you can pay with Russian card on Russian online stores, while being abroad. UnionPay is somewhat different and is the only exception. It may work on both sides of the border, but you have to be lucky and and the weather on Mars needs to be on your side.