About the D21 method

The D21 method is a modern voting system that makes group decision-making more efficient. It allows voter to cast multiple votes, and in certain cases also includes a minus vote. With a larger range of votes, voters can express their preferences more accurately and thus achieve voting results that best reflect their interests.

How does it work?

The basic assumption of the D21 method is that each voter always has more votes available than there are winning options. All votes have equal weight and a voter may or may not use all of them. Only one vote can be cast for each of the options. In order to grant a minus vote, it is necessary to give at least two plus votes. The number of plus and minus votes may vary depending on the specific poll. Modifications always occur according to the algorithm, the author of which is the Czech mathematician Karel Janeček.


Due to the effect of multiple votes in the D21 method, the option that the most voters agree on wins. The minus vote reveals controversial options that may have many supporters but also opponents. This weakens populists, extremists and other candidates who divide society. This is what makes the D21 method unique compared to traditional electoral systems.

Why do we use the D21 voting system?

More votes allow us to better express our opinion. By choosing only one option, we say only one word. By giving out more votes, we answer with a whole sentence. In addition, we express our willingness to agree with others.

Basic rules of the method:

  • The voter has more votes than there are winning options or elected mandates.
  • Only one vote per option can be cast.
  • All votes have the same absolute value.
  • The voter can choose to use all of their votes or just a part of them.
  • The voter can cast a minus vote to an option he disagrees with. In order to cast a minus vote one must cast at least two plus votes.
  • The number of plus and minus votes is governed by the algorithm of the D21 method in order to achieve a consensus result.

Read more about the D21 method in the expert article written by its author Karel Janeček.