Passive points and respec

Where the points come from

1 point per level, from level 2 to 100: 99 points.
Quest points, 22 in all, each granted once per character: 1 for finishing the tutorial; 2 for each full act (I to V, VII and IX, one for the main quest and one for the boss); 1 each for the half-acts VI and VIII; 1 for the first kill of each of the four pinnacle bosses; 1 for the first kill of Voruun Hale.
Total at level 100: 121. At level 68, when the first map opens, you have about 84.

Quest points are refunded and re-spent exactly like level points.

Respec

You can take points back at any time in a hub.

Refunding one point costs 5 gold per character level (never less than 50 gold).
Up to character level 20, it is free. Experiment while you are young.
An Orb of Regret refunds one point with no gold cost. They drop from monsters (Currency and orbs).
Respeccing is not allowed inside maps or arenas.

Ascendancy points are separate. They have their own pool and their own respec rules (Ascendancies).

Spell effects of respeccing. If you respec a Signature Spell keystone and lose a glyph slot, the surplus glyph returns to your backpack. If your backpack is full, the respec is refused so that nothing is lost (Glyphs).

Tip. Take a look at the nearest notable of a cluster before spending the dead-end node after it. The cheapest strong choices lie two nodes from a cluster's entrance (The passive tree).

After a season ends your tree moves intact into Standard, and you get one free complete respec on migration (The Standard realm).