If the top card of that library changes while you're casting a spell, playing a land, or activating an ability, you can't look at the new top card until you finish doing so
Green Ramp: The Gold Standard Green excels at ramping by getting as many lands as possible as quickly as possible to cast massive creatures
Goblin Tunneler: limited needs this, it can also go well with a strong one or two drop that needs to deal combat damage to an opponent for a bonus
For example, removal-heavy decks tend to have a headache against decks that don't care too much for the battlefield (like control decks), or decks that are happy to fill their graveyard (like reanimator decks), or decks that can sacrifice creatures when their enemies point removal at them (like aristocrat Commander decks)
In Murderous Redcap infinite damage win-con with Anafenza, Kin-Tree Spirit
Last year there was Chaos Wrap, which is based off Chaos Warp