You will receive zero Resources from successful Raids in only two cases:
- You have reached your Raid Limit (the number of Raids you can send per day)
- You have reached the Resource Raiding limit
If Units return from successful Raids completely empty-handed, it is almost certain that you have hit one of these limits. While there are messages that will inform you when you have reached a limit, they will not be shown if you carry out Raids directly from your Battle Reports.
The amount of Resources you can gain from raiding other players is limited:
- You can claim a maximum of 500,000 Resources from Bases in any 24 hour period.
- You can claim a maximum of 50,000 Resources from a single Base in any 7 day period.
These numbers are aggregate (net) totals. They take into account Resources lost as well as Resources gained.
For example, if a player raids 10,000 Resources from you, you will be able to take up to 60,000 Resources from them within the next week, so that you will have gained a net total of 50,000 from them.