Old Alliance

If you control either an Elf or a Dwarf but not
both, you may search your library for one
creature card of the other type, put it in your
hand, and shuffle.
If you don't control one of either creature type,
you may search your library for an Elf or a
Dwarf, put it into your hand, and shuffle.
If you have both an Elf and a Dwarf on
the battlefield, draw three cards.