It's no secret or question that dealing damage has been heavily focused around critical hits. It's the reason CHC and CHD are massively popular (read: necessary) stats, as well as the reason that many top builds rely on or are best suited to take advantage of high CHC and CHD, and by consequence is the reason that itemization and build diversity is so stagnant. Fixing the problem can be done in two ways: nerfing CHC/CHD, which has been tossed around but would only lead to people doing less damage across the board and requiring players to completely re-gear their characters; or by buffing or introducing other ways of dealing damage.

So how can we buff damage without just making CHC/CHD that much stronger? Easy: by putting the power behind different gates, power which cannot benefit from crit, but can be equally or similarly strong. Where a critical hit is a buffed attack, these new sources of power would be essentially bonus damage that are dealt alongside regular attacks, like a second hit. I've come up with a few examples:

• Crowd Control on-hit damage: Attacking a crowd-controlled enemy (slowed, stunned, knockbacked, blinded, feared, etc.) deals bonus damage to the enemy equal to X% of the attack (cannot crit).

• Elemental synergy damage: Attacking an enemy with an element marks the enemy for a short time. Using that element's Synergy Element on a marked enemy deals bonus damage equal to X% of the attack (cannot crit).

• Agility damage: Moving builds up stacks of Agility (up to a cap) based on distance traveled. Attacking an enemy consumes X stacks and deals bonus damage equal to X% of the attack (cannot crit).

• Relentless damage: Attacking an enemy with a Primary attack marks the enemy for a short time. Successive Primary attacks on that enemy add additional marks and deal bonus damage to the enemy equal to X% of the attack (cannot crit). Stacks are reset upon using a Primary attack on another enemy.

The point of these new sources of damage is to enable new builds and playstyles, from a high-crowd control build dealing bonus damage with every hit, to a Fire-and-Ice Wizard taking advantage of elemental synergies, to a perma-rolling DH applying Agility stacks with every attack, to a single-target focused Barbarian shredding through an army of demons one at a time. These ideas not only enable new builds, but enable synergy among multiple bonuses (I'm sure there's more than enough potential for a CCohD/Elemental synergy), and also don't require a nerf or invalidation of CHC/CHD builds. In fact, it's more than possible that you can have high CHC/CHD and still take advantage of one of these new power sources, like a high-Agility DH with high CHC/CHD.

And when it comes to the implementation of these stats, Blizzard would have their choice - as a Primary affix, a Secondary affix, a regular gem effect on weapons or gear, a Legendary/Set item affix, or as a Legendary gem effect on weapons or gear. Hell, they could even introduce a new section of Paragon points for these stats. If Blizzard wants to give (read: force) players new choices besides CHC/CHD, it could even be a combination of primary affix and gem effect.

There's potential for many more types of bonus damage, I'm sure, and if you have any suggestions feel free to add them in the comments, as well as any concerns or adjustments to the system.

Edit: clarity/readability