The main ways of double experience
1. Gain from main missions, branch missions, such double experience can not be traded, and mostly the missions are very boring and trifle. Every one get the same quantity, like the treasure mission in King valley. And human fish mission and Nile branch missions, etc.
2. Daily missions like dark attach and practice cavern. The dark attach mission is very boring and trifle, if you are not in a team, it will be time-wasted job. While it has a 50% proportion to get double experience in practice cavern mission. But the SL must be doubled, that is to say, there is a 50% chance to use 30 minutes double experience.
3.So far, the only way to get double experience which can be traded is draw a lottery. People will good luck could have a try. The double experience here is similar as a valuables worth 1000 Battle of the immortals Gold.
4. Exchange double experience with SuNin ambassador, the exchange rate is as high as 99.9%. If RP exploded, may luckily get a sunin baby, whose rate is only 0.1%.
5. Activities by Wanmei, like a exploration, I believe some people must have get 10-20 double experience already. And this activity is held in the second month every month. Which is a better chance compared with collect enough articles for 3W boi gold.
6. The 300 minutes presented each week. And remember use all these 30 minutes before weekend, or it will be cancelled automatically by system..