5e has some pretty cringeworthy design decisions made in the name of legacy, which has led me to coming up with a few houserules for what I see are the worst issues.
Attacks of Opportunity
You can now make an Attack of Opportunity as an Opportunity Action. Every characters can make one Opportunity Action per Turn. Using Opportunity Actions does not affect your Reactions. As well, casting a spell that does not make an attack roll now provokes an Attack of Opportunity.
Only one AoO a round, when AoO damage is already made low because of the way damage scales based on the number of attacks you make, is baffling. Moreso when plenty of classes need their Reaction for other things. That, and casting a fireball in melee should be harder than a firebolt.
Healing Surges
Instead of hitdice, all characters will have a number of healing surges. Characters have a number of surges based on their class, plus their constitution modifier.
Fighter:10
Rogue:8
Cleric:8
Wizard:6
Healing Surges have a value equal to 1/4th of max HP, rounded down. Anytime a character receives a healing effect, they can choose to spend a surge to enhance the effect by this value. For instance, if a level 5 fighter with 60 hp used Second Wind and spent a healing surge, they would heal 1d10+5 from Second Wind, plus 15 from the healing surge.
Healing Surges can also be spent at any time during a short rest. All healing surges recover after a long rest.
Hit Dice provide such meager healing that they really do make a cleric required if a party wants to have more than one or two moderately challenging fights a day. Healing Surges were elegant and good.
Short Rests
Short rests are 5 minutes.
Having the fighter need a whole hour while the other three classes can go at nearly full power all day is dumb. If Second Wind bothers you, limit it to only be used when at half health or lower
Strength
If you possess a strength score of 15 or more, your carrying capacity becomes equal to your strength score times 100 instead of 15. So with 20 strength, you could carry 2,000lbs of equipment and lift, push, or drag 4,000lbs
Add half your strength modifier, rounded up, to Constitution and Dexterity saving throws.
Strength loses out a lot against dexterity, as this thread http://www.enworld.org/forum/showthread.php?356698-So-Is-The-Dex-Based-Fighter-Just-Strictly-Better&prefixid=dndnext clearly shows.
Charisma
You can use Charisma instead when a saving throw calls for Wisdom.
Because all saving throws were not created equal, and fighting off a mind control spell with the force of will just makes sense.
Attacks of Opportunity
You can now make an Attack of Opportunity as an Opportunity Action. Every characters can make one Opportunity Action per Turn. Using Opportunity Actions does not affect your Reactions. As well, casting a spell that does not make an attack roll now provokes an Attack of Opportunity.
Only one AoO a round, when AoO damage is already made low because of the way damage scales based on the number of attacks you make, is baffling. Moreso when plenty of classes need their Reaction for other things. That, and casting a fireball in melee should be harder than a firebolt.
Healing Surges
Instead of hitdice, all characters will have a number of healing surges. Characters have a number of surges based on their class, plus their constitution modifier.
Fighter:10
Rogue:8
Cleric:8
Wizard:6
Healing Surges have a value equal to 1/4th of max HP, rounded down. Anytime a character receives a healing effect, they can choose to spend a surge to enhance the effect by this value. For instance, if a level 5 fighter with 60 hp used Second Wind and spent a healing surge, they would heal 1d10+5 from Second Wind, plus 15 from the healing surge.
Healing Surges can also be spent at any time during a short rest. All healing surges recover after a long rest.
Hit Dice provide such meager healing that they really do make a cleric required if a party wants to have more than one or two moderately challenging fights a day. Healing Surges were elegant and good.
Short Rests
Short rests are 5 minutes.
Having the fighter need a whole hour while the other three classes can go at nearly full power all day is dumb. If Second Wind bothers you, limit it to only be used when at half health or lower
Strength
If you possess a strength score of 15 or more, your carrying capacity becomes equal to your strength score times 100 instead of 15. So with 20 strength, you could carry 2,000lbs of equipment and lift, push, or drag 4,000lbs
Add half your strength modifier, rounded up, to Constitution and Dexterity saving throws.
Strength loses out a lot against dexterity, as this thread http://www.enworld.org/forum/showthread.php?356698-So-Is-The-Dex-Based-Fighter-Just-Strictly-Better&prefixid=dndnext clearly shows.
Charisma
You can use Charisma instead when a saving throw calls for Wisdom.
Because all saving throws were not created equal, and fighting off a mind control spell with the force of will just makes sense.