The voting experiment may proceed. That was the word Thursday from the Minnesota Supreme Court about instant-runoff voting, aka ranked-choice voting, as embraced by a lopsided majority of Minneapolis voters in 2006.

That should also be the word today from the Minneapolis City Council. The charter amendment city voters approved authorizes the council to put the brakes on the new voting system only if it deems that the city is not ready for the change.

The council has reasons for qualms about eliminating the primary and allowing voters to rank candidates in order of preference this November. It will be complicated -- especially as voters seek to fill two seats on the Board of Estimate and Taxation and three citywide seats on the Park and Recreation Board. It will require a hand count, and that could mean weeks of waiting for results. It will require considerable voter education -- and is bound to be confusing to some voters, regardless of how much explaining is done before Election Day.

Add to that the recent resignation of the city's respected elections director, Cindy Reichert, and it's understandable that council members -- who themselves are on the ballot this fall -- would have cold feet.

But they should also recognize that the switch to instant-runoff voting (IRV) is not theirs to decide. The decision was made three years ago by 65 percent of the city's voters. The charter spells out the one permissible reason for elected officials to delay: a finding that elections officials are not ready to implement the system.

A test election has been completed. In the absence of suitable vote-counting machines, a manual counting method has been devised. Public education money has been set aside. As of Thursday, all legal challenges have been cleared away. The city is ready to roll out IRV.

We refer to what will ensue this fall as an "experiment," while acknowledging that in Minneapolis, it is much more than that. It's a provision in the city's governing charter. But it also will make Minneapolis a voting-method laboratory for the rest of the state to observe, critique and potentially mimic.

Interest in ranked-choice voting has swelled in Minnesota in the 11 years since the Independence Party's Jesse Ventura "shocked the world" and junked the assumption that majority votes would decide Minnesota gubernatorial elections. The last three gubernatorial races have been won by pluralities of less than 50 percent.

A nonmajority winner is not possible in a single-seat election that uses IRV. It allows voters to rank candidates in order of preference, then sorts the secondary choices of ballots cast for last-place finishers in a series of "virtual runoffs," until one candidate passes the 50 percent threshhold.

That feature has made the vote-by-number method attractive both to third parties, which believe it gives their candidates a chance for more votes, and some elements of the two dominant parties, which believe the method will minimize the threat that third-party candidates pose to their ultimate victories.

Claims that instant-runoff voting is not constitutionally permissible were flatly rejected by the state's high court. Writing for a unanimous panel, Chief Justice Eric Magnuson dispatched each of six objections raised by the conservative-backed Minnesota Voters Alliance. The clarity of the chief justice's description of IRV should be useful to those who ought now be assigned to explain the change to voters in the Minneapolis election this Nov. 3.