I have opened a chest with common and epic item, but the club reward was a common item. Is this normal??? I have read that reward club items have the same quality or more as the highest quality of the items in the chest
No, as rare as the rarity of any guaranteed rarity - I believe that regular adventure chests lack a guaranteed rarity (or rather, guarantees common+), adventure gold chest are uncommon - if they don't contain a special set rarity drop (Melvelous legendary for instance). Final Treasure Hunt chests have a guaranteed epic rarity first time you beat them, then they go back to regular adventure rarity status. MP chests have the guaranteed rarity mentioned on the track, and Quest Gold chests have a rare rarity. (I believe we could do with better colour coded chest consistency btw)
Actually, just ignore the chest colors in the campaign. MP and purchased chests will tell you what the rarity is. In the campaign, 2 item chests have no guarantee, final chest of a dungeon is guaranteed Uncommon unless it's a guaranteed drop (like treasure hunts), quests are guaranteed Rare.
That's basically exact the same thing I said. Just saying. Just raising the issue of making chest colours consistent - as that's probably confusing people.
to the point about chest colors, Chain Chronicle (a SEGA app game only, supposedly, available in Japan) has a very clear chest code system: 1. wooden chest - only drops common and uncommon cards, 1 star to 2 stars 2. silver chest - drops 3 stars rare cards 3. gold chest - drops 4 stars super rare (SR) and they have 5 stars super super rare (SSR) cards. so of course they notion of rare and uncommon are different to here but it is very clear what you will get just looking at the chest.