This thread is dedicated to implementing simple rules to end the divide.

I will start with three general rules and some changes for the fighter and the monk.

• Fighter, Monk, Rogue and Barbarian:
• Get a feat every even class level.
• Get extra attack at levels 5, 9, 13 and 17.
• Melee attack penalty:
• Can give penalty to attacks of magnitude smaller or equal to class level.
• Double the magnitude of the penalty and add it to damage.
• Has to choose the penalty before the roll.
• Fighter:
• Also get feats at levels 3, 7 and 15.
• Also feats extra attack at levels 11 and 20.
• Monk:
• Amount of ki points equals class level plus 4.

General homebrews explanation:

• Spells give casters infinite versatility. What casters have via spells, martial could have via feats. It would make them stronger, more customizable and have more options. 
• I think it is really interesting how casters keep gaining more slots and higher levels of spells, but martials only improve their damage at level 5 and then never again. It should be a continuous improvement.
• The melee attack penalty would make melee martials, hands down, the best at single-target damage (what they should've been from the start). Also, it takes away the necessity of Great Weapon Master (buffing sword & board, the monk, and the rogue), and it justifies melee over ranged martial.
• I would say the best thing about those buffs is that they really only become powerful past level 5, where the martial-caster divide usually occurs. Hopefully, at least, they can ****** the total divide to around the 17th level instead of around the 13th.
• Another very good thing is that they are extremely simple to implement.

Fighter homebrew explanation:

• The fighter is the class that gains more feats and more attacks. Naturally, now that every other martial gains more feats and attacks, he would have to gain even more extra stuff.

Monk homebrew explanation:

• Even with all of the buffs, Monks are still weaker than other martials. Having 6 Ki points at level two is very great, considering the average encounter has around 4-5 rounds. At the 5th level, having 9 Ki points, the Monk can have his good features at any time, even face two encounters in a roll without needing a short rest.

It actually makes things more balanced, good job on this point. I adopt this system without any hesitation !

Personally I use a system where Martials get an extra damage dice (or two in case of Greatsword), when Proficiency goes up. So 1d8 becomes 2d8s, 3d8s, etc, Greatsword 2d6 becomes 4d6, 6d6, etc. Simple and seems to scale well.

Quote from Macilrille >>

Personally I use a system where Martials get an extra damage dice (or two in case of Greatsword), when Proficiency goes up. So 1d8 becomes 2d8s, 3d8s, etc, Greatsword 2d6 becomes 4d6, 6d6, etc. Simple and seems to scale well.

 but then monks would either be literally the worst martial by far, or literally the best (6d12 damage x 5 attacks???)

I miswrote. I do it on the levels where Cantrips gain extra damage, so 7th 11th 15th. Monks in my games are nerfed, we play in a homebrew world inspired by Tolkien, History, and various fantasy settings. I am a military historian, and HEMA and competetive reenactment fighting practitioner, and to me it seems ridiculous that some Karate practitioner can run up and punch a guy in armour made to withstand poleaxes, and damage him.

Anyways, it is 7th, 11th and 15th martial damage go up.

In my experience, martials hold up fine in combat at high levels. What needs to be fixed is out of combat utility. The martials sit there picking their noses while the casters talk to gods and spy on enemies and create mansions. Everything martials can do out of combat can also be done (and often better through spells) by casters.

If we truly want equality, we need to pare back on spells that give casters physical mastery on top of mental mastery (Knock, Jump, Telekinesis, Spider Climb, etc.), and probably give martials some additional toolkit that they can use to overcome the problems that can't be solved by stabbing them.

But there are way too many sacred cows here for it to ever happen. 4e was as close as we're ever going to get and people flipped out over it. So generally I try to solve it by giving martials magic items that have high utility.

If you want to narrow the "martial/caster divide" the best way would be to reduce the power level of the casters.  Power creep has hit this game HARD over the different editions and turning martials into even more cartoonish parodies of themselves wouldn't improve the game in my opinion.

Quote from Macilrille >>

I miswrote. I do it on the levels where Cantrips gain extra damage, so 7th 11th 15th. Monks in my games are nerfed, we play in a homebrew world inspired by Tolkien, History, and various fantasy settings. I am a military historian, and HEMA and competetive reenactment fighting practitioner, and to me it seems ridiculous that some Karate practitioner can run up and punch a guy in armour made to withstand poleaxes, and damage him.

Anyways, it is 7th, 11th and 15th martial damage go up.

 Cantrips scale at 5th, 11th, and 17th.