Strikes are Sift's way of being consistent without being silent. When someone crosses the line, they get points. Enough points trigger the next step on the ladder you configured in /setup.
The default ladder
Out of the box, points stack toward a timeout at 3, a kick at 14 and a ban at 20. Each point expires after 30 days unless you pick a different window. That means a member who had one bad week is not still paying for it months later.
Before the kick or ban
Sift DMs the member before a kick or ban lands, when Discord can reach them. If they already left, Sift does not pretend a timeout worked. Small details, but they cut down on "why am I banned?" tickets.
Your server, your numbers
Some communities want a hard line on slurs and a soft line on spam. Others skip escalation entirely and use Sift only for case cards. /settings opens the strike panel: thresholds, points per category and expiry. Set a step to 0 to skip it, or all three to handle everything by hand.