Battlefields are special cards - They are spells.
Only one Battlefield can be active at once and they affect both player!
If a second Battlefield is played the first one will get destroyed.
(The background where you play cards will change it look.)
Some Neutral Battlefields →
Uldum:
https://hearthcards.ams3.digitaloceanspaces.com/76/dc/fc/d8/76dcfcd8.png
Ulduar:
https://hearthcards.ams3.digitaloceanspaces.com/24/7c/ad/25/247cad25.png
Echo isles:
https://hearthcards.ams3.digitaloceanspaces.com/9b/bb/f7/79/9bbbf779.png
Some Class Battlefields →
Swamp:
https://hearthcards.ams3.digitaloceanspaces.com/cb/a8/4f/ae/cba84fae.png
Dragon Mountain:
https://hearthcards.ams3.digitaloceanspaces.com/cd/69/1b/1f/cd691b1f.png
The Nexus:
https://hearthcards.ams3.digitaloceanspaces.com/f2/f5/a9/f2/f2f5a9f2.png
Some Battlefield Minions →
Shaman of the Earthen Ring:
https://hearthcards.ams3.digitaloceanspaces.com/45/24/7f/0f/45247f0f.png
The white shark:
https://hearthcards.ams3.digitaloceanspaces.com/7a/77/d2/8d/7a77d28d.png
Algalon:
https://hearthcards.ams3.digitaloceanspaces.com/4c/28/e3/e5/4c28e3e5.png
Here is one more weapon for you →
Thunderfury:
https://hearthcards.ams3.digitaloceanspaces.com/c7/3b/85/36/c73b8536.png
Now Blizzard can add each location, each forest, each town… Each dungeon and raid as Battlefield card with very cool effects.
Maybe a higher trust level can post this pictures so you dont have click on each link.