If you've got a land in your party—well, lands can't be party members, but you can certainly be rewarded each time one enters the battlefield under your control. The landfall ability word highlights these abilities for you. An ability word appears in italics and has no rules meaning.

There ain't no party like an adventuring party, and the expedition houses of Zendikar strongly encourage you to take a well-formed party on your journey. You never know when you'll need someone to heal you, sneak around, deliver a good solid punch, or harness the mystical forces that make up the very fabric of the Multiverse to produce the perfect cup of tea.

Threshold abilities care about you having seven or more cards in your graveyard. Some threshold abilities are, like the one Crypt Feaster has, a triggered ability. Whenever Crypt Feaster attacks, its ability checks to see if there are seven or more cards in your graveyard. If there are, the ability triggers and goes onto the stack. Players can respond to this ability with instants or activated abilities.

If you've got a Wizard in your party, you may be rewarded for casting certain spells that Wizards like: instants, sorceries, and even more Wizards.