Is there a difference between Thunder, Force, and Bludgeoning damage?

Question

Inspired by this answer, is there a precedent for when to use Thunder vs Force vs Bludgeoning damage when designing monsters, traps, or spells? The damage types as is are very similar, and it can be a bit difficult to differentiate between effects.

Answer 1

As I was writing my question, I realized that my clarifications and self research were becoming an answer of their own:

Bludgeoning

Definition on PHB p. 196:

Blunt force attacks—hammers, falling, constriction, and the like—deal bludgeoning damage.

Caused by blunt physical impacts or weight by a tangible thing. Examples:

• Maces, clubs, sling stones, rocks, or fists (or launched items, like in Catapult)
• Being crushed or squeezed (e.g. Maximillian's Earthen Grasp, Bones of the Earth, or Bigby's Hand: Grasping hand)
• Falling from a height and colliding with the ground
• Objects dropped onto a creature (e.g. Transmute Rock, Storm of Vengeance's hail, "Rocks fall, everyone dies")
• Impact with water, or the result of being pushed around by water, particularly via spells (e.g. Monk's Water Whip, and Tidal Wave)
• Impact with objects or the sheer force in a whirlpool or whirlwind (e.g. Whirlwind, Control Water, Storm Sphere

Force

Definition on PHB p. 196:

Force is pure magical energy focused into a damaging form. Most effects that deal force damage are spells, including magic missile and spiritual weapon.

Caused by a strike of concentrated or tangible magical energy. Alternatively, caused by ending a turn in an object or creature as an incorporeal creature, or similarly having a mishap while teleporting (which could be construed as the same thing). Examples:

• Concentrated energy (Magic Missile, Eldritch Blast, Disintegrate)
• Strike of tangible magical energy (Spiritual Weapon, Bigby's Hand, Mordenkainen's Sword)
• Occupying a space while incorporeal (Specter, Wraith, Shadow Demon)
• Teleport mishaps

Thunder

Definition on PHB p. 196:

A concussive burst of sound, such as the effect of the thunderwave spell, deals thunder damage.

Caused by a sonic boom, or otherwise extremely loud sound, representing the concussive force and damaging effect on the ear. This is a very rare damage type but can also be created by arbitrary elemental effect spells. Examples:

• Sonic boom (Thunderwave, Shatter, Storm of Vengeance)
• Arbitrary damage type spells (Chromatic Orb, Glyph of Warding)