Activate any basic land you control by tapping it, adding ({1} magic symbol) .
Activate Earthcraft by tapping a creature, untapping the basic land.
Activate Perilous Forays by paying ({1} magic symbol) and sacrificing the tapped creature, searching your library for a land card with a basic land type and putting it onto the battlefield tapped.
The land enters the battlefield, triggering Zendikar's Roil, creating a 2/2 Elemental creature token.
Repeat.
Results
Near-infinite death triggers.
Near-infinite ETB.
Near-infinite landfall triggers.
Near-infinite LTB.
Near-infinite sacrifice triggers.
Put all land cards with basic land types from your library onto the battlefield tapped.