What moves can't or always Critical Hit?

Question

Example: Dragon Rage can't Critical Hit, but Frost Breath always does.

Answer 1

Moves with guaranteed base power can't critical-hit.

Dragon Rage, Sonicboom, Night Shade, etc.

Storm Throw and Frost BReath will always critical hit.

inflicts damage and will always result in a critical hit unless the
target has Battle Armor, Shell Armor, or is under the effect of Lucky
Chant.

http://bulbapedia.bulbagarden.net/wiki/Storm_Throw

http://bulbapedia.bulbagarden.net/wiki/Frost_Breath_(move)