AutoMod: Mass Mention

What it does

This is disabled by default. When enabled, Discord can perform actions whenever a user mentions too many users or roles in a single message. The threshold for what counts as “too many” is configurable.

It counts unique mentions, so mentioning the same user twice still counts as one mention. It sums the total number of unique users and roles mentioned, then compares that against your threshold.

If the threshold is met, you can choose a combination of actions to perform:

Block the message from being sent.
Optionally show a small notice message to the user when blocked.
Send an alert to a pre-defined channel — for example, to notify staff.
Time the member out for a limited time.

You can also choose channels, categories, and roles where the rule is ignored.

Anyone with the Administrator or Manage Server permission is always ignored. If some of your staff don’t have these permissions, you may need to add their role(s) to the ignore list.

Discord’s mass-mention protection vs. a bot’s

Bots may offer more control over mentions, exceptions, and so on, but one benefit of using Discord’s system is that it can prevent the message from even being published. Other bots can’t do this — at best they delete the message automatically, but by that point users and roles may already have received a ping notification. By using Discord for this, you can prevent ghost pings.

Mention raid detection

This extra option in the AutoMod rule lets Discord use mass-mentions as an additional indicator of raids. Discord doesn’t provide much information about how this works.