no strings attached

From strings (“(figurative) conditions, limitations, restrictions”), possibly from an old prank where a money purse with a hidden string would be placed on the ground, and pulled away when someone tried to pick it up.

• "For a friend I’ll help out for free, no strings attached."
• "In the present century marriage is preceded by a betrothment, gifts are usually interchanged (but with no strings attached), and a causeless withdrawal therefrom by either party is considered infamous."
• "Mr. [James Gillespie] Blaine's declination—it is always understood that we assume there is no string attached to his letter—is undoubtedly a wise move on his part."
• "Listen. We've kept it quiet, but she's in with the elect on French Hill. Her claim's prospected the richest of the outfit. Present indication half a million at least. In her own name, no strings attached. Couldn't she take that and go anywhere in the world and reinstate herself?"
• ""No," I assured him, after receiving his cordial welcome, "my offer had no string attached. I'm more than ready to help in any way I can, to find a niche for you in this old town and fit you into it. It doesn't matter where you hail from, or how you got here; New York is an all-comers' race, and the devil take the hindmost.""
• "Would he ask her out (if he ever did) just for herself, no strings attached?"
• "As to the $12 billion State share, there is not even the pretense of an attempt at congressional oversight, Federal control, or standards of performance. The State share is totally no-string attached."
• "Who wanna have sex with no strings attached"
• "'I asked him to think again. I asked him to put Drago's interests first. I repeated that there were no strings attached to my offer.' / 'No visible strings, you mean.'"
• "You say that you want / All of my love / But let's be honest, we don't need all that / I like it better with no strings attached"
• "He also criticised what he called the Government's "bailout" of the privatised rail companies with no strings attached, stating: "There is simply no reason why the same easy solution could not have been applied to London,[…].""
• "When government delivers handouts with no string attached, more people naturally want to use and abuse them, which eventually ruins economy and drains a country's wealth. Essentially the welfare state destroys the ethic which sustains this very state."

• unconditionally
• ziplessly

• no questions asked
• quid pro quo
• pull the strings