"If you've ever wondered about the origins of this chant - used to call in all players at the end of a game of hide-and-seek - be advised that the experts only have a partial answer to your lifelong puzzlement. Word sleuths are fairly certain that the 'oxen' (or 'octen') in the call is simply a childish corruption of 'all in.' The rest remains a mystery." From "Encyclopedia of Word and Phrase Origins" by Robert Hendrickson (Facts on File, New York, 1997).
http://www.phrases.org.uk/bulletin_board/11/messages/665.html
Olly olly oxen free is a phrase used in children's games, which is generally used to indicate that people who are hiding (in a game of hide and seek, for example) can safely come out into the open.
The exact origin of the phrase is unknown, but etymologists suspect it is a childish corruption of a phrase that would have made more sense in the Hide-and-seek context; such as "all ye, all ye, oxen free!", "all in free", "outs in free", "all set free", "All ye all ye outs in free", "All ye, all ye, outs are free", or "All the, all the outs in free"; or possibly a corruption of the German "Alle, alle auch sind frei", (literally, "Everyone, everyone also is free").
The phrase can also be used to coordinate hidden players in the game "kick the can", where a group of children hide within a given radius and a "seeker" is left to guard a can filled with rocks. The seeker has to try to find the "hiders" without allowing them to sneak in and kick the can.
http://en.wikipedia.org/wiki/Oly_oly_oxen_free
Psychology:
Oly Oly Oxen Free was a secret amongst the Spartans; none but they and a select few outsiders knew it. Those outsiders were close to the Spartan's family; such as Dr. Catherine Halsey, Cortana, Sergeant Johnson and Chief Petty Officer Mendez. Thus, the signal was extremely important to each Spartan; they would rather die than give up the significance of the tone, which could potentially be used to betray or endanger their teammates.
Uses:
The term Oly Oly Oxen Free was used on numerous occasions throughout Halo: The Fall of Reach and Halo: First Strike. Some of the times it was used are as follows:
* After the Spartan Team had beaten Tango Company, and John-117 had checked to make sure their evacuation point was all clear.
* After the Battle of Reach, Anton-044 used it as an S.O.S. signal over the E-Band.
* For the Spartans to enter CASTLE Base, Kelly-087 used it to let Dr. Halsey know it was them.
* During Operation: FIRST STRIKE, Linda-058 used it to let John know where she was so he could pick her up.
* At the end of Operation: FIRST STRIKE, Sergeant Johnson used it to let Blue team know where the Gettysburg was holding station behind a nearby moon.
* When the rest of Blue team, minus John-117 arrives on Onyx, Kelly whispers it over the COM, except she whispers "Olly Olly Oxen Free" with two L's
Non-Canon:
Marines use it on the level "The Ark" when firing on the first Covenant encampment, but only if the IWHBYD Skull is activated.
Trivia:
* Dana Awbrey alludes to this phrase by titling a blog post "Olly Olly Axon Free".
* Oly Oly Oxen Free was originally used to tell players in a game of hide and seek that the game was over and they could come out of hiding.
* Sometimes in Tom Clancy's Splinter Cell, if you shoot an enemy and then hide, they will say "Oly oly oxen free! Come out, come out wherever you are!".
http://halo.wikia.com/wiki/Oly_Oly_Oxen_Free
The exact origin of the phrase is unknown, but etymologists suspect it is a childish corruption of a phrase that would have made more sense in the Hide-and-seek context; such as "all ye, all ye, oxen free!", "all in free", "outs in free", "all set free", "All ye all ye outs in free", "All ye, all ye, outs are free", or "All the, all the outs in free"; or possibly a corruption of the German "Alle, alle auch sind frei", (literally, "Everyone, everyone also is free").
http://eduqna.com/Words-Wordplay/2950-Words-Wordplay-7.html
Latin:
"Lingua oro ut vos volo quispiam ut sanus amo is est gravis..."
(Oly Oly Oxen Free... All out in the open, we're all free...)
It was used in when playing hide and seek by children.
It probably started out as "All-ee, all-ee, outs in free," a call from the person who was "it" letting those hidden (the outs) know it was safe to come in. The -ee was added for emphasis and for its piercing quality. There are many regional variations, most of them the product of dialectical interference or regional preference.
Variations include
Ollie Ollie in come free,
Oly Oly oxen free,
Ollie Ollie oxenfreed,
Alley Alley oats in free,
Oly Oly ocean free,
All-ye All-ye outs in free,
Oly Oly Olsen's free.
That last one comes from Minnesota.
Its root seems to be an English-Norman French-Dutch/German concoction: "Alles, Alles, in kommen frei"or "Oyez, oyez, in kommen frei!"
"Allez, allez" was a Norman addition to the English language, pronounced "ollie, ollie" and sometimes written "oyez, oyez" and meaning "everyone." "In kommen frei" was a phrase popular in Dutch/German New York and Pennsylvania, where many Zonians came from, meaning "come in free."
One guess is that the original was something like all in free for all who are out can come in free, to indicate that the person who is it in the game of hide-and-seek has caught somebody to become the new it, and so everybody else can come out of hiding without the risk of being caught.
In a typical version of Hide-and-Go-Seek (as played in the US Midwest) children playing the game chose a tree, a gatepost or the edge of a wall as "Home," and selected one player as "It". He (or she) put his head on his arm at Home, to cover his eyes; and began to count loudly to some limit such as 25, giving the others some 25 seconds in which to hide "Out" in the general vicinity. He then announced, "Ready or not, here I come!", and tried to locate an Out to race Home. An Out who could race Home first, was "Home Free"; he then waited at Home for the game to end while the player who was It tried to locate another Out. If the player who was It won the race Home, the Out who lost this race became It. They then called, "All 'e, all 'e Outs In Free!" (or "oly-oly-oxen free") to bring the rest of the players Home, and restart the game with the new It; or call off the game for the day. It was an old saying that kids said during the Oregn Trail times.
