I was a big fan of how 4e gave Martial characters interesting attack options that had an impact on the battlefield besides "damage" and was sad to see how this was stripped from them with each subsequent 5e playtest. I know some players prefer "Martial" characters to make nothing but melee attacks that only deal damage, but that honestly is pretty boring.
You're simplifying things a bit.
The attack options were stripped out in response to playtest feedback. The Martial Damage Dice were cool, but playtest feedback showed that people generally felt they were "wasting" their dice by using them on anything but damage. Because tripping or stopping reactions or blinding are nice, but the best status condition to put on a creature is always "dead".
My personal perspective is that I don't want fighters and martials only dealing damage. Buuut... I don't want certain maneuvers codified in the rules. If there is a dedicated "trip" manoeuvre, it generally means you can't trip someone without that power. Or you have to make tripping so ineffectual or have such a high cost it's not worth doing.
The more you work under the assumption that you can only do the codified powers on your character sheet, the less you can do... anything else. It's trading the infinite possibilities of imagination for two to five hard coded options.
To that end I've designed a series of "Martial Techniques" more or less equivalent in power to the various caster Cantrips, especially those in the SCAG, for classes of the more martial persuasion to gain. My biggest goal was to avoid stepping on the Battlemaster Fighter's toes. These certainly dip into her area of expertise, but don't gain any Superiority Dice bonuses, functioning more like "At-Wills" from 4e than anything else. This is a first pass, and I'm planning to let the group I DM for use these at our next game.
Okay, let's take a look at the design.
First nitpick "basic attack" isn't a term in 5e. It doesn't mean anything. The phrase "On your turn, decide if you will use a technique, a basic attack, or some other ability." should probably simply read "As an action, you can use a technique." (I'm not sure why the techniques all have an "attack speed" anyway, given it's always 1 action.)
Also, because it's not an "Attack action" it would cut out anything that triggers off that. Like two-weapon fighting. So you don't need to call that exception out in the rules.
The long list of specifically exempt features is problematic. Any time you need to give a "but..." to a rule, that means the rule isn't concise and generally means it needs to be revised or rephrased.
Many of the restrictions seem unnecessary. Why can't a ranger cast a bonus action spell at the same time? Especially if these are balanced as a cantrip. Now, I imagine this is so you don't combine
hunter's mark with the attack. But this is a kludge balance fix, and there's no in-world reason the spell ceases to function for one round when the ranger decides to use a technique instead or a regular attack. This just leads to rule questions: does the spell end? Does it just not have any effect and resumed the next round? That's just weird.
Cutting the rogue's Cunning Action is just strange. It's an unrelated action. And still doesn't really balance well with the rogue in terms of DPR.
This also stacks completely with the Champion fighter with no restriction. It's straight power creep.
As mentioned earlier, I'm not sure why there's an "attack speed". Or why there's a "target" mentioned either. That just seems to be there to match the formatting of cantrips, but isn't necessary as there's no techniques that take 1 minute or target the self or an object. Although, I suppose there *could* be.
Upon writing that, thus actually makes me think. Why can't a fighter use a technique against an object? Devastating Blow could be used on a door.
The overall problem with this design is the majority of powers are damage
plus. You deal the regular damage of an attack
plus the extra effect, which is supposedly to be roughly equivalent to a cantrip's bonus.
However, cantrips generally don't add their caster's ability score bonus to damage. Cantrips justify their extra effect by being lower damage. *Some* casters can add an ability score, but that's as a result of a class feature. Gaining the extra damage to cantrips comes at the expense of another feature or ability.
This isn't the case with this. Across the board this just lets the martial characters deal full damage
and have a kicker effect. There's no cost or trade off. Except the odd list of exceptions that may or may not actually come into play in any given round. Not being able use Reckless Attack isn't an issue when you're raging anyway, or hitting a low AC target. A restriction that doesn't restrict makes for poor balance.
The extra damage at higher levels is odd and problematic.
The extra damage in cantrips is there to help keep casters in line with multiple attacks. I'm not sure the design works as well here.
First, the static damage dice is a damage boost to small dice weapons (daggers, short swords) but a damage drop to most two-handed weapons. Someone like the barbarian takes a big damage hit when they get Extra Attack to use this. It's also all-nothing: a barbarian or great weapon fighter has one chance to deal 2d6+1d8+4 damage once or two chances to do 2d6+4 damage. The average damage is fairly close, but there's a better chance of hitting at least once
and the maximum damage if the barbarian hits with both attacks is much higher. Plus with two attack rolls there's a greater chance of a critical.
However... after level 11 things changes as all classes but the fighter no longer gain extra attacks. So the techniques experience a jump in power. I imagine this is why rangers and paladins can't use spells, but the barbarian is not as limited.
There's also the rogue issue. Rogues don't get multiple attacks. Their damage increases via sneak attack instead. So they get a flat damage boost from these attacks. There zero reason not to spam a technique. Especially for an assassin, since the bonus dice would double on a critical as well!
And multiclassing becomes an issue as well. Since damage scales up automatically, there's less need to get Extra Attack.
With the above in mind, if I were designing these techniques, I'd remove the action limitation and instead have the techniques do less damage. On a hit, a character can choose to forego their ability score modifier to damage to apply the benefits of a technique (or just the ability score and no weapon dice for some). Reduced damage in favour of more effects. And because the added effect comes with a set cost that always has to be paid for every technique, there can be fewer restrictions on other class features.
Thoughts on specific techniques:
Clever Slash. This is the Help action plus damage, and likely too strong. "Ally" isn't a term used in 5e. It tends to be "friendly creature" or "allied creature". You should be able to see and hear the ally as well, and a range should be specified.
Devastating Blow. Wasn't the point of this to give martials something else to do except damage. The "moar damage!" technique goes against that design.
Diminishing Strike. Does not interact well with the marking rules from the DMG. If marking is desired, those should probably be used.
Feather Me Yon Wretch. The ally making the attack should have to use their reaction.
Footwork Lure. 5 feet in any direction? Straight up!
Hamstring seems to have been cut away. It actually looks like quite a bit of text is on a secondary page that isn't visible.
Nimble Strike. What's a "square"? "At any point in this movement you may make a melee attack..." How is that different from the normal rules for attacking mid-movement.
Shield Bash. 1d8 damage for a shield seems high. There's some good design here, as it's not *just* making a shield attack, which anyone could be able to do. I'd phrase it so your ally also gains an AC bonus from your shield rather than a static +2. That way magic shields protect more
and an ally already using a shield won't double up the benefits.
Tide of Iron. The narrative of this one is weird. If you're slamming them down with your shield, shouldn't you be making a shield attack. As written, you have a shield, you hit them with your sword, and they fall down.
Run Down. This is weird. So, you move 15-45 feet (since you can move during an action), potentially zigzagging through enemies to provoke as many attacks as possible, and then hit a fleeing target. And it takes extra damage. Why does it take this extra damage? How does your being more hurt in the last two seconds mean your attack does extra damage?
Vengeance Strike. Again with the extra damage...
Ardent Shield. Why isn't this just a paladin spell? Okay, paladins don't get cantrips, but there could be a variant paladin or an oath that does. Fitting this in here feels like a square peg in a round hole.
