This object exists primarily within the Sonic X continuity.
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
The Selection Machine is one of Dr. Eggman's machines in Sonic X. Eggman uses it to help him select one of his robots when he needs them.
The Selection Machine's function is to randomly select one of Eggman's robots whenever he needed one to help him with his plans to conquering the world or at least defeat Sonic the Hedgehog and his friends. It highly resembles a slot machine and is built into his base. To activate it, Eggman places a deck of robot cards into a slot, closes the hatch, and pulls a lever to start the slot machine spinning.
In "Little Chao Lost," it was seen as a stand-alone machine carried by Decoe until the doctor ordered him to unpack his knapsack. He used it to pick out E-66 Da-Dai-Oh during his vacation to attack those who were camping with Tails.