Ace of Spades is a level 40 Exotic Hand Cannon. Only Hunters can acquire this weapon. Ace of Spades can be acquired from completing the Rank 3 gunsmith quest Back in the Saddle as a Hunter. Players need to be rank 3 with Gunsmith before obtaining this quest.
The weapons from destiny only slightly resemble familiar guns, but they combine so many different colours and new mechanisms to create a whole new outcome of firepower. Every weapon in the game is different (in abilities and appearance), so a unique design for each material, barrel, and additional specs is key.