What is the penalty for missing a day of stoning?

Missing a day of stoning (Rami) at the জামারাত does not invalidate your হজ্জ, but it does require compensation. The stoning on the Days of Tashreeq is considered wajib (ওয়াজিব) জমহুর উলামাদের মতে, not a pillar (rukn), so missing it requires fidyah but does not void the হজ্জ.

If you miss the stoning on one day, you can make it up the following day. Perform the missed day's stoning first (all three pillars in sequence), then perform the current day's stoning. The stoning must be done in chronological order — you cannot stone for day 12 before completing day 11. All makeup stoning must be completed before sunset on the 13th of Dhul Hijjah (the last day of Tashreeq). If you departed মিনা early on the 12th, the deadline is sunset on the 12th.

If stoning is missed entirely and cannot be made up within the allowed time period, a fidyah (sacrifice of a sheep in মক্কা মুকাররমা) is required জমহুর উলামাদের মতে. The Hanafi school holds that missing even one day's stoning without excuse requires dam (sacrifice). If the stoning was missed due to a valid excuse (severe illness, disability), then appointing a proxy is the proper course of action rather than paying fidyah after the fact. In all cases, the হজ্জ remains valid.