Accumulator bet - a bet on the  several outcomes of different events. The winning amount on an accumulator bet is the amount of the bet multiplied by the accumulator odds. The accumulator odds are calculated as a multiplication of all the outcomes of all the events included in such an accumulator bet. An accumulator bet is deemed to have won if all outcomes in all the events included in the accumulator bet have been correctly predicted. If one of the outcomes in the accumulator bet loses, then this results in the entire accumulator bet losing.

For example, Accumulator is made on that four teams to win in appropriate events with the odds indicated in the table:

If four teams win, winning will be equal to multiplication of bet stake and total odds. If one of the team loses, bet is lost. If one or more outcomes are settled as refund for any reasons, that ourcome will be exluded from combo bet and its odds will be equal to 1(one) and total odds will be recalculated. 

Also, bonus is added to combo bet. Bonus - A special event with fixed odds which may be added by the Bookmaker to multiple bets with accumulated odds of a minimum of 2.50. The value of the bonus depends on the number of selections in the multiple bet: 

The following restrictions are applied for the accumulator bonus:

a) If one or more of the events in the multiple bet are calculated as a refund and, as a result, the accumulated odds are reduced to less than 2.50, the bonus is also calculated as a refund;
b) In the event that one or more selections within a multiple bet are settled as a refund, the odds of the bonus applied are adjusted accordingly. For example, if in a multiple bet of ten selections, one selection is settled as a refund, the odds of the bonus applied are adjusted to 1.09;
c) Bonus is added on bets placed via internet accounts only;
d) Bonus is added to all Pre-match, Live events and mix bets.