These will be your creatures, sorceries, instants, enchantments, artifacts, etc
It is particularly strong in Limited, and I see the creature hit the battlefield (often through Sneak Attack effects or cards like Reanimate) in LSV's Vintage draft videos all the time
While Child of Alara is still a powerful commander, this 6/6 for WUBRG (One White, Blue, Black, Red, and Green mana) and its ability to destroy all nonland permanents upon death, isnt all that exciting
Creatures you control get +1/+0 until end of turn
As a result, it may take a while to earn the in-game currency you need to build the deck you want
The difficulty comes in sculpting a board state where you will get to play the Gambit for that effect, as you basically need to keep four mana up at all times