Seven Dwarves — ruling 1

Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to one Seven Dwarves may become lethal if another Seven Dwarves you control leaves the battlefield during that turn.

Seven Dwarves — ruling 2

The last ability of Seven Dwarves lets you ignore the "four-of" rule. It doesn't let you ignore format legality. For example, during a Throne of Eldraine Limited event, you can't add Seven Dwarves from your personal collection, no matter how happy they would be.

Seven Dwarves — ruling 3

If you're fortunate enough to open or draft eight or more Seven Dwarves during a Limited event, you can include only seven of them in your deck. The rest remain in your sideboard.

Seven Dwarves : règles, fonctionnement et interactions (MTG)

Seven Dwarves is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

This creature gets +1/+1 for each other creature named Seven Dwarves you control. A deck can have up to seven cards named Seven Dwarves.

How it works : Seven Dwarves

Original English text — Wizards of the Coast / Scryfall

#1October 4, 2019· Wizards of the Coast
Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to one Seven Dwarves may become lethal if another Seven Dwarves you control leaves the battlefield during that turn.
No other card is named in this ruling.
#2October 4, 2019· Wizards of the Coast
The last ability of Seven Dwarves lets you ignore the "four-of" rule. It doesn't let you ignore format legality. For example, during a Throne of Eldraine Limited event, you can't add Seven Dwarves from your personal collection, no matter how happy they would be.
No other card is named in this ruling.
#3October 4, 2019· Wizards of the Coast
If you're fortunate enough to open or draft eight or more Seven Dwarves during a Limited event, you can include only seven of them in your deck. The rest remain in your sideboard.
No other card is named in this ruling.

Interactions with other cards

These cards' text mentions Seven Dwarves.

Jewel Mine Overseer

When Jewel Mine Overseer enters, conjure seven cards named Seven Dwarves on top of your library. They perpetually gain "When this creature enters, draw a card." Then shuffle. At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.