House ordered most of the vault to be filled with concrete. House gained access to the vault, he stripped much of its technology, and with the help of the vault dwellers, used it to rebuild the Strip. After a game of blackjack that lasted for many hours, those in favor of opening to the outside won in an extremely risky move. House's offer challenged each level's representative who were in favor of staying isolated. While most of the vault dwellers wanted to refuse the offer, some residents were in favor of it. In 2274, Robert House contacted Vault 21's residents with an offer of inclusion in the resurrection of Vegas.
However, as with all utopias, the peace was not lasting. Reliance on luck to solve problems created what might be considered the perfect realization of anarchy: a society in which everyone is equal and no one has an advantage over the others. Chosen representatives gambled against each other in the main atrium and the winner earned the right to settle the dispute as wished by the collective. Everyone in the vault was equal, it was created with a perfectly symmetrical layout, and all conflicts and problems were solved through gambling.
Located in downtown Las Vegas, Nevada, Vault 21 was one of the few vaults that successfully protected its inhabitants while fulfilling the parameters of its experiment.