Is Chainsaw legal in Standard, Modern, and Commander?

Chainsaw is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Chainsaw

Q: What type of card is Chainsaw?

Chainsaw is an Artifact — Equipment. Its oracle text reads: "When this Equipment enters, it deals 3 damage to up to one target creature. Whenever one or more creatures die, put a rev counter on this Equipment. Equipped creature gets +X/+0, where X is the number of rev counters on this Equipment. Equip {3}"