Scavenger hunts are most interesting events in this game and they are very rare becouse it requires more work and creativity in implementing them.
We never had alliance scavenger hunt event ( i hope we will some day). Here is idea, each alliance is tryingto get more points for better alliance rewards in this event. Only alliance leader or someone authorized would post on forum screenshots of compleated tasks. Here is example:
-Have minimum 30 Earls in alliance store
-Have minimum 20 Duke's in alliance store
-Top 10 in alliance "Today's contribution ranking" have minimum 300 points each
- Have at least 3 green wonders
-Have at least 5 "rivalry" diplomatic relations
- Accept one new member
-Have at least 5 alliance victories in a row (Alliance- Achievement-Combat events)
- Send alliance announcement with massage "Alliance Scavenger Hunt is fun"
- Take screenshot of at least 5 different alliance players playing "geography" in alliance chat.
- Take screenshot of battle report with atleast 3 diferent alliance players participating
- Have atleast 5 players in Members" list with activity 100% (or more) on one page.
P.S. IF GMs decide to go create this event i have many more ideas for tasks, so contact me via mail