On his YouTube channel, veteran programmer and RPG designer Tim Cain reveals a bit more background on his and his team's initial plans for the Fallout vaults.The Interplay staff envisioned 1,000 Vault Tec vaults in the United States were envisioned to be located in the United States. This number has logistical problems, both in-game and in reality, which Cain explores: "This is just me talking, it's not legitimate."

First and foremost, the number 1,000 was simply an aesthetic choice. The only reason this pin was placed in the original game was when Leonard [Boyarsky, lead artist on Fallout 1] was making the vault suit and he asked me how many digits he needed to leave on the back." Cain said. 'And Cain said. [I'm a programmer, so I start counting from zero.

The idea that there is a "vault zero" speaks to a tidbit of Fallout lore that Cain previously shared on his YouTube channel. I initially considered the LA Test Vaults in Fallout 1 as a candidate for Vault Zero, but apparently there is a definite "Vault Zero" in Fallout Tactics.

Cain also casually dropped that another keystone of Fallout's lore was born out of stylistic concerns: the 13 "federations" of Fallout's more cruel and brutal America were created after Fallout's artists designed a 13-star American flag for the game which was created after the game was released. According to Leonard, (the "Fallout" art team) just did it because it looked cool.

But even with 1,000 vaults in the US, Vault Tec would not have saved that many people. By Cain's calculations, it would be about "one-third of 1%" of the U.S. population.

"If each vault held 1,000 people, Vault Tec's vaults would save only 1 million people, far less than the population we had imagined.

Also, while artistic license and deceptive scale are definitely at play in these games, I think there were about a dozen people in Vault 101 in "Fallout 3." They all came to my birthday party.

Anyway, looking at the density of vaults in the games, Cain believes that even the best-case scenario of 1,000 vaults is unlikely; since the entire state of California appears in "Fallout 1" and "Fallout 2," there are theoretically at least 20 between the two games. There should be at least 20 vaults; Fallout 1 and Fallout 2 combined only had about four to six clearly defined vaults. And that's if you count the unnumbered ones, like what Harold's vaults were."

The TV show added four more in Cali, but that's still only half of the minimum 20 expected for a populous state, and the rest of the game is not much better in terms of vault density. Cain believes there is a cosmically plausible explanation: they did not build all 1,000 vaults, nor did they come close."

"Vault Tec built less than half, and probably far fewer than the number of vaults they envisioned. Cain likened the company to the countless real-life government contractors who bid lowest in our vaunted public-private partnerships and have since underperformed. Cain concluded, "I think it's far fewer than a thousand companies."

Referring to the Fallout wiki, 41 vaults are featured in the game and TV show, and recently ranked 26 vaults from worst to best - two on the wiki's list from Fallout: Brotherhood of Steel (ie, Hey Hey Hey), minus the Museum of Technology exhibit from Fallout 3 and the Securitron Bunker from Mr. House in New Vegas.

Meanwhile, the Vault Tec map displayed at the show, analyzed by Reddit's Werthead, shows about 120 vaults in the US and Canada, far fewer than Cain's original estimate. So if any of this is binding, it is definitely not. Because this is all fiction. Not counting Fallout: Brotherhood of Steel yet.