How many obligatory acts of Hajj are there, and what are they?

There are 9, as follows:

(1) Performing Sa‘i. (According to many, this is a pillar of Hajj.)

(2) Entering into Ihram before passing the Miqat.

(3) Remaining at ‘Arafat until sunset.

(4) Spending the night at Muzdalifah.

(5) Spending at least two nights at Mina after Muzdalifah.

(6) Throwing the pebbles.

(7) Slaughtering the Hady (sacrificial animal) (for those performing Tamattu‘ and Qiran Hajj).

(8) Cutting the hair.

(9) The Farewell Tawaf.