Explorer's Scope

My biggest criticism is that it doesn't actually protect or enhance the creature that it's attached to-- a 1/1 dork is still a 1/1 dork. The good news is that because it triggers off attacking and not damage, you get your chance at an extra land even if the creature that it's on is being sent to an obvious death.
The obvious tactic is to attach it to a creature with a landfall ability, such as Plated Geopede, and swing and hope for a landfall bonus to carry into battle. Frankly, if you don't care about landfall, this is an awfully strange means of accelerating your mana, and a random one-- you could end up with seven lands on turn four via Raging Goblin, or never get a thing for your troubles. Best used in conjunction with top-o'-the-deck tricks like Ponder or Sensei's Divining Top, but can also be useful in Vampire Nocturnus decks (to get an offending land off the top) or Oracle of Mul Daya decks (to get a potential third land each turn). Would arguably be much better if there were an Uproot effect in Standard.

Constructed- 2
Casual- 3
Limited- 3.5
Multiplayer- 3.25

Explorer's Scope

In the classic novel "The Hobbit," Bilbo Baggins leaves his house without even a handkerchief but ends up saving the kingdom anyway. Those were different times, and if you try that in Zendikar, they will never find any part of you. Don't leave home without your equipment - and a way to trigger landfall abilities during combat.

Constructed: 2/5
Casual: 3/5
Multiplayer: 2/5
Limited: 4/5

Explorer's Scope

I think this card is underevaluated in limited situations where you have a good aggressive deck. In Zendikar-Zendikar-Zendikar draft you are often playing aggressive decks. Often it is silly not to attack with everyone. In the right drafted deck or sealed deck, this can be a good card to have. It triggers landfall. Not much of a card elsewhere.

Constructed: 2
Casual: 2
Limited: 3
Multiplayer: 1

Today's card of the day is Explorer's Scope a one mana equipment that equips for one making it fairly cheap for the type. Being colorless it can be used in many decks such as Kor, Landfall, or anything that depends on extra lands in play. While not as consistent as other mana acceleration options being repeatable makes this card stand out in the right situations. For most decks about one third to one half of the available cards will be land, giving this effect a decent average of succeeding.

In Constructed and Casual this isn't reliable or powerful enough to see much play. Some themes may run it, but I don't see any format being particularly impacted by this artifact. Casual may make greater efforts to make use of the effect, but outside of multiple attacks in the turn I don't see many ways of breaking the effect.

With Limited the smaller pool and in set Landfall ability make this a bit more playable. As possible acceleration for any color it is a fair draft pick in Sealed, generally after removal and bombs. With Sealed this can be slipped into almost any offensive deck as a cheap equipment and potential source of extra lands in play. It is unlikely any card will be wasted on destroying the Scope, unless no other option exists, so it is almost assured to recover the cost in lands gained. I suggest running it when able and you may be pleasantly surprised.

For Multiplayer the attack requirement really holds it back in the often more defensive and political environment. Equipping a creature that has Vigilance can cover for the weakness some of the time, but attacking every turn is rarely a good multiplayer strategy which leaves a card like this vastly underpowered.

Constructed: 2.5
Casual: 3.0
Limited: 4.0
Multiplayer: 1.5