Is Great Wall legal in Standard, Modern, and Commander?

Great Wall is legal in: Legacy, Vintage, Commander.

What type of card is Great Wall?

Great Wall is an Enchantment. Its oracle text reads: "Creatures with plainswalk can be blocked as though they didn't have plainswalk."

Enchantment

Creatures with plainswalk can be blocked as though they didn't have plainswalk.

Set Legends

Rarity Uncommon

Artist Sandra Everingham

Enchantment Commander Legacy Vintage