Weapon Skills for Old-School Fighters

Fighters in old-school D&D are powerful, but they're mechanically pretty dull. You get...better at hitting stuff, and better at avoiding death and dismemberment. That's it.

This is one potential way to make them more interesting and adding nuance to how they play in combat.

You know how "specialists" in LotFP have skills that you can improve by filling in pips on six-sided dice as they level up? What if fighters had weapon skills--that only they have access to--based on the properties of whatever weapon they happened to be using?

It would work like this: when you roll a d20 to make an attack role with your fighter, you also roll a d6 for their weapon skill at the same time. If the d20 indicates a hit and the d6 roll is equal to or less than the number of pips they have in the corresponding weapon skill, the attack is a hit and deals damage, plus the weapon's special property comes into play.

Some examples of possible weapon skills/properties:

Assail -- when this weapon property activates you can make a second attack against the same foe, but you do not get to roll your weapon skill die for this bonus attack. 
Weapons that might have this property: dagger, sling, quarterstaff

Brutal -- when this weapon property activates you can roll twice for damage against your foe and take the higher result.
Weapons that might have this property: battle axe, maul, claymore

Defend -- when this weapon property activates your armor class improves by one point until the start of your next turn.
Weapons that might have this property: poleaxe, dueling sword, main gauche

Hack -- when this weapon property activates you get a +2 bonus to your next attack against the same foe.
Weapons that might have this property: sword, axe, falchion

Stagger -- when this weapon property activates you cause your foe to drop one spot lower in initiative order. (I'm assuming d6 per side initiative.) If your foe's initiative drops below 1, it is stunned for one round and must roll initiative again on its next turn.
Weapons that might have this property: flail, mace, warhammer

Weaken -- when this weapon property activates your foe's armor class gets worse by one point.
Weapons that might have this property: spear, planson, longbow

I'd assume that fighter's start with one pip in each weapon skill, since they're trained in using all weaponry. Not sure about the rate they should gain pips to spend on improving those skills yet; this is all untested material in the spitballing stage.

Playing Card Initiative in MY Retro-Clone?

It's more likely than you think.

One of the things I like best about Savage Worlds (and want to import to other systems where possible) is the use of playing cards for initiative. When using individual dice rolls for initiative sometimes it’s hard to see who rolled what from across the table; playing cards have the advantage of being big and bright enough to make initiative order readily apparent.

Here’s how I’d do playing cards for initiative in old-school D&D-like games that have some sort of small-range bonus to initiative rolls. For example, B/X has the optional initiative modifiers that you could use for this. When a new round of combat starts, each player is dealt a card; if the character has a bonus to initiative rolls, they get a number of extra cards equal to that bonus. Here’s an example of what initiative might look like for a party of four characters:

The character whose initiative cards are on the far left (an agile rogue) got one card just for being involved in the combat, and then two more cards for having an initiative bonus of +2. The next character, a quick-witt‚ed warrior, got the standard card and a bonus one for their initiative bonus of +1. The next, a mage untrained in the art of war, has no initiative bonus, and thus only gets one card. The last character, a deft ranger, has a +1 initiative bonus and gets an extra card because of it.

Players then arrange their cards highest to lowest; high card goes first, and everyone follows in descending order. Alternately, if a player would rather take their turn on a lower value card than their highest, that’s okay too.

In the case of a tie, break it in alphabetical order of the suits: Clubs beats Diamonds beats Hearts beats Spades.

What about that Joker? A player who gets the Joker on their turn can act whenever they want in initiative order and gets to re-roll any one roll during the round. Fortune favors fools.

For foes controlled by the GM, instead of dealing cards for each enemy, deal them into groups based on their types. For example, if the GM has 4 Mud Ghouls (initiative bonus +1) and their leader Morgash of Tarr (initiative bonus +0) in the fray, the GM’s initiative cards would look like this:

One pile for all the Mud Ghouls, one pile for Morgash.
So, bringing it all together, here’s the initiative order for the round:
1st - Warrior - Joker
2nd - Mud Ghouls - Ace of Diamonds
3rd - Rogue - Aces of Spades
4th - Ranger - 10
5th - Morgash of Tar - 9
6th - Mage - 8

Easy, right?

I recommend having two shuffled decks on hand with different backs; that way if you run out of cards you don’t have to stop and shuffle...just break out the other deck and keep going. Sort out the cards after the game, or have a player shuffle the deck you ran through after they’ve taken their turn.