is there a limitation on how many copies of same card your allowed in one magic deck

[Caterpie]

is there a limitation on how many copies of the same card you're allowed in one magic deck?

[Sphinx]

Up to 4 copies of a single card
Though basic lands like moutnains and plains you can have as many copies as you want

[seba1983]

yep that right. no more than 4 of every cardname (english cardname is unsed here).

exeptions are the basic lands (plain, island, swamp, mountain, forest), the snow-coverd basics (snow-coverd plain, snow-coverd island, snow-coverd swamp, snow-coverd mountain, snow-coverd forest) and Relentless Rats due to thier card text.