DeletedUser3515
I've read somewhere (can't remember where) that loot chests are won in adventures. I've played quite a few adventures so far, won most of them and I haven't received any loot chest yet.
DeletedUser
Only 20% chance to get a loot box after you won in an adventure. So it can take a lot of wins before getting a loot box 
DeletedUser36559
20% does not necessarily mean 1 in 5 just to let you know. I've done 100 battles so far and only received 6 loot chests so that's a 6% probability for me.
Deleted User - 3853873
Ya when I got my achievement for 100 battles I looked at my chest count and with the ones I won and I also bought,which was 1 about every 25 fights at least ,my total was only at 16,so i got them 12% of the time.Now if I counted yesterday I did it all day and until wee hours of the morning and only got 2 lol.
DeletedUser
I think it's more than just winning the adventure. your performance in the adventure also matters. I find myself getting a box if I manage to kill 3 times in an adventure, for example.
Deleted User - 3853873
dont think has anything to with how many building you have or how many ko you have,it is all chance on wether you get a chest to drop.one day i might get one every 5 or 6 fights and usually always win,the next day go all day winning and get none.havent got a piece of outlaw since first day,since its been mostly taxrefunds or mojos