Gauntlet II was the 1986 arcade followup to the original Gauntlet. Some game manufacturers make the mistake of changing too many things when they make a sequel, but luckily Atari didn't do that.
Gauntlet II actually uses the same engine and platform as the original Gauntlet. They pretty much just took the Gauntlet and made all new levels, and coded in a character select routine, which allows any player to play any character.
This is actually the version of Gauntlet that most of the famous quotes came from. The original Gauntlet did not mention the player's color when speaking, but this one did, allowing for such gems as Blue Warrior needs food badly! Blue Warrior is about to die.
There is a good chance that this is actually the Gauntlet that you remember playing in the arcade. The original Gauntlet came out in 1985. Then the Gauntlet II conversion kit came out a year later in 1986. A lot of Gauntlet machines got switched over to Gauntlet II. They tended to stay as Gauntlet II for a rather long time, due to the relative scarcity of kits that would convert a Gauntlet cabinet. Well, the proper kits were scarce until about 1989 when 4 player games started taking off in a big way. Even today I still encounter more Gauntlet II's than original Gauntlets.
As far as hardware is concerned this game ran on the exact same boardset, which the exception of the security chip (which was different). A normal Gauntlet boardset will function with Gauntlet II EPROMS up to level 6, at which point it will reset, replacing the security chip will allow the boardset to be converted fully.
Atari loved to run contests. This game had a built in contest where you could win either a t-shirt or a $5000 savings bond. You get the chance to enter if you are able to find a secret room and finish the secret mission given to you upon entering the room. The game would then display a 6 digit number that you were supposed to write down and send to Atari to claim your prize. Only the first 500 players were eligible to win. S.T.U.N. Runner and many other games had similar contests.