Chesapeake Beach Park Bingo Bell Big-Ten & early mass medal machines

I am unsure where it at all quite started and who was the first.  

In the late 1950s and through the 60s the UK would produce a number of mass gambling machines.

In the 1970s,Taito, Sega and others promoted MiMo systems: Medal In Medal Out systems, where customers could purchase medals to play gambling games with, but there was no cashing them out.  (There were places that used these machines illegally to gamble for cash, of course, but the vast majority were legit medal parlors)  Medal games are still a huge force today within the Japanese market, and any gambling or game fan visiting Japan should spend time in a medal parlor.

Multi-player gambling devices have always been a staple.  Some of the earliest slot machines were designed to accept multiple nickels to allow multiple players to bet at the same time.

1904 Peerless Floor Roulette Slot by Caille
7-way action means 7 coins can be played, by 1 to 7 players.

But what these machines did not have were separate stations for each player.  Everyone could crowd around, but there was a single point of access to betting.  It would only be later that each player could have their own separate spot where betting and payouts were handled separately for each.  Only with separate interfaces do I truly consider them as multiplayer/mass gambling machines.

Caille even butted up against legislation that would limit the number of machines on the floor, creating double (or even triple) machines, but I still do not consider these quite as mass gambling machines as each player does not have their own console.

1904 Mills catalog: The Mills Twins
12-way action, allowing nickel play on one side and quarter play on the other.  (betting a quarter in 1904 would be like betting $35 today)

Post-WW2, while the USA was cracking down (and cracking skulls) on gambling, the UK permitted low-stakes gambling in their arcades, producing a number of marvelous multiplayer gambling machines.

Penny Roulette by Whittaker

Japan began importing these machines in the late 1960s, and by early 1970s we find advertisements showcasing the possibilities of operating these machines within Japan.  Due to gambling laws there, the machines could not be used for gambling, and the idea of a "medal parlor" was born: customers pay ('rent') medals to play the elaborate gambling machines, but they couldn't exchange the medals for currency.  It was just for fun, and advertised as high-class civilized entertainment that gave a taste of the mystique of gambling.

Carnival Plaza System flyer from ジャパンオーバーシーズビジネス (Japan Overseas Business)
All of the machines advertised were imports from then UK.

By 1974, Japan was making their own mass gambling machines.  Nazox2016 discusses Japan's first domestic medal machine here. (archive)

an example of Taito MiMo machines circa 1975

In the USA markets one of the inadvertent key innovators was Maryland in the 1950s.  From Lemons, Cherries and Bell Fruits by Dick Bueschel:

6 Bells by Ramsdell

Here is a webpage that has a brief (legalese) summary of the Maryland laws pertaining to slot machines.  The pages linked to within do not work, but this page could be utilized to look up the legislation elsewhere.  (archive)

10-player Winterbook console by Ramsdell

This is all preface for an amazing machine that recently came up on Facebook Marketplace for a 1960s Chesapeake Beach Park Bingo Bell Big-Ten.  (this is posted in the Coin Op Connections group, so you might have to join that first before seeing)

The seller says it is 16' long, 61" tall, and could be split up to just use 5 machines if so desired.

Each player had their own control console for betting and their own payout chutes.  But there was only a single set of reels, which all 10 players played simultaneously.

inside!