Leatherhead
Possibly a Idiot.
Apologies in advance to all the colorblind people out there, I needed more formatting options because words have more than one meaning.
I have noticed when talking about action economy, people tend to say things like "But Haste exists, therefore action economy is broken!" And when discussing things like that new Tunnel Fighter, people aren't quite sure what kind of action it is, leading to people thinking it is a Free Action, or a Bonus Action taken out of turn somehow.
Well, that's actually not at all true, what is happening is that some characters are using one type of action and/or limited resources to pay for another type of action, at a premium.
Lets go down the list of things you can do in a Round. Remember: A Turn is for you, and a Round is when the entire table has a Turn. That gets confusing sometimes, I know.
You will notice that I worded that list in a strange order, that's because the order goes from "Most valuable" to "Least valuable" parts of the turn. Note the quotation marks: That one time when you saved the multiverce with a Free Action Speech isn't in the scope of typical play, nor the scope of this discussion. You should go post that in the Story Hour Forum if you still feel the need. Your character is probably not using all of their turn up during the round. With 8 kinds of different things (or more) that can potentially happen, some of which have to be triggered, and some can be broken up into multiple different stages, it is bound that a few of them are going to slip through the cracks. Most people are happy if they can get the Action, Move, Bonus Action, and Concentration down pat.
Now that you know what is possible, it is time to discuss what trading away your time does for you.
In regards to Haste: You spend your Concentration, and an Action, and your spell slot, in order to give a buff to the target's Action (but only when attacking) and Move. Basically it's good for Barbarians and Paladins, classes or characters that get lots of bonus damage on all of their attacks, but only a few attacks per turn. Fighters and Rogues, in contrast, get very little DPR boost from a single extra attack, because of how their mechanics work. Obviously, such a trade off can be worth it, or else nobody would ever do it. But it doesn't actually give you more time in a round, just better use of two actions at a cost.
For another example, Flaming Sphere uses your trio of Concentration/Action/spell slot, so the caster can subsequently use Bonus Actions to make other people burn to death.
These are how the action economy is supposed to work: Trade a higher action (and other stuff) for boost to a lower action, or for an opportunity to use one of the triggered action types.
Tunnel Fighter is an odd duck. Probably because it's from UA. It uses a Bonus Action to enter a "stance" until the start of your next turn, basically an entire round. While in this stance you can make Opportunity Attacks without spending your reaction (that One "Reaction Point" I talked about up there). Additionally you can spend your reaction to make an (untyped) melee Attack against creatures that move more than 5' while in your reach.
Stances have no associated mechanic. It's not in the action list, and there is no rule for how many stances you can use. Stances were the Martial power source's equivalent to concentration back in 4e. The cost is rather clear, most of the characters who use attacks, love to get Bonus Action Attacks, and while they aren't the greatest source of damage, it is something that everyone will care about. As opposed to concentration, which most Fighters don't even have a use for to begin with, and multi-class Barbarians can't use anyway. Come to think of it, it's a bit strange you can maintain a stance and rage at the same time. It's also a bit strange you can be rendered incapacitated, then "healed" and still maintain it.
Tunnel Fighter lets you have limitless Opportunity Attacks, at the cost of your Bonus Action. It also gives you a single more powerful variation of an Opportunity Attack, which can be used when the target is forced to move, or when they shift around inside your reach, because it's an untyped attack with no rules other than what this feat explicitly describes. To be fair, most of the time, you aren't going to get all of those OAs. But, with the help of your team, you will get a use for your Reaction (which can be quite rare with some DM's) and even generate quite a few free hits in the process.
Tunnel Fighter actually generates more actions, and can significantly slow down combat. It's also full of holes. (What is a stance anyway?) I would call it broken, but not in the "overpowered" meaning. Just the "this thing doesn't work right" meaning.
Conjure spells, are another kind of broken thing. In that they generate tons of actions by virtue of summoning lots of creatures to fight. They also slow down combat a bunch, which is kinda bad.
And then there are Beastmaster Rangers, which have had all kinds of threads about how they aren't actually worth what you trade into them. For an example of how things can be broken in the other direction.
I have noticed when talking about action economy, people tend to say things like "But Haste exists, therefore action economy is broken!" And when discussing things like that new Tunnel Fighter, people aren't quite sure what kind of action it is, leading to people thinking it is a Free Action, or a Bonus Action taken out of turn somehow.
Well, that's actually not at all true, what is happening is that some characters are using one type of action and/or limited resources to pay for another type of action, at a premium.
Lets go down the list of things you can do in a Round. Remember: A Turn is for you, and a Round is when the entire table has a Turn. That gets confusing sometimes, I know.
- Concentration: Passively doing something important. Think of this as your PC with a ton of peripherals, but only one USB port to plug them all into. You can end concentration at any time with no action at all. Concentration is broken when you cast another spell (or use an ability/power) that requires concentration, whenever you take damage (Con save DC 10 or 1/2 of the damage you took, whichever is higher, to negate) When you are incapacitated (status) or killed, and any time the DM feels like it shouldn't be possible. Also, you can't concentrate on two spells at once.
- Action: This is where the action happens, literally. Your attacks, most spells, important item use, and even running away for your life all key off this part.
- Move: Not actually an action. You can move before, during, or after your Action and/or any other parts of your turn. You can even use multiple types of movement on your turn if you posses them.
- Bonus Action: Should be called "Schrödinger's Action" Seeing as how these things don't actually exist until triggered by something. In general, they are weaker than Actions, and the harder they are to trigger the stronger they get. Bonus Actions can can be done at any time during your turn, unless they have a specific trigger, and can't happen if you cannot perform Actions. Like if you are stunned. You can only perform one of these a turn, even if you have multiple ways of triggering them.
- Reaction: Similar to the Bonus Action, these don't happen unless they are triggered by something. Unlike the Bonus Action, you start of your turn with one "Reaction point" (to spend on a single Reaction), and they don't refresh until the start of your next turn. Note: If you can somehow take more than one turn per round, you would get a Reaction for each of those turns. Mostly used for OAs or defensive powers. The limit of one is to keep combat fast.
- Interaction: Opening doors, drawing weapons. Once per turn you can ready a simple object for proper use as part of your Move or Action. There is a handy list on PHB190 for examples on how simple.
- Non Action: Some powers, spells, or odd rules combinations give your character something to do which does not cost you any time in a turn.
- Communication Flourish: A.K.A "Free Action." Talking, basically. Any idea you can convey in about 6 seconds doesn't cost you a more significant part of your turn.
You will notice that I worded that list in a strange order, that's because the order goes from "Most valuable" to "Least valuable" parts of the turn. Note the quotation marks: That one time when you saved the multiverce with a Free Action Speech isn't in the scope of typical play, nor the scope of this discussion. You should go post that in the Story Hour Forum if you still feel the need. Your character is probably not using all of their turn up during the round. With 8 kinds of different things (or more) that can potentially happen, some of which have to be triggered, and some can be broken up into multiple different stages, it is bound that a few of them are going to slip through the cracks. Most people are happy if they can get the Action, Move, Bonus Action, and Concentration down pat.
Now that you know what is possible, it is time to discuss what trading away your time does for you.
In regards to Haste: You spend your Concentration, and an Action, and your spell slot, in order to give a buff to the target's Action (but only when attacking) and Move. Basically it's good for Barbarians and Paladins, classes or characters that get lots of bonus damage on all of their attacks, but only a few attacks per turn. Fighters and Rogues, in contrast, get very little DPR boost from a single extra attack, because of how their mechanics work. Obviously, such a trade off can be worth it, or else nobody would ever do it. But it doesn't actually give you more time in a round, just better use of two actions at a cost.
For another example, Flaming Sphere uses your trio of Concentration/Action/spell slot, so the caster can subsequently use Bonus Actions to make other people burn to death.
These are how the action economy is supposed to work: Trade a higher action (and other stuff) for boost to a lower action, or for an opportunity to use one of the triggered action types.
Tunnel Fighter is an odd duck. Probably because it's from UA. It uses a Bonus Action to enter a "stance" until the start of your next turn, basically an entire round. While in this stance you can make Opportunity Attacks without spending your reaction (that One "Reaction Point" I talked about up there). Additionally you can spend your reaction to make an (untyped) melee Attack against creatures that move more than 5' while in your reach.
Stances have no associated mechanic. It's not in the action list, and there is no rule for how many stances you can use. Stances were the Martial power source's equivalent to concentration back in 4e. The cost is rather clear, most of the characters who use attacks, love to get Bonus Action Attacks, and while they aren't the greatest source of damage, it is something that everyone will care about. As opposed to concentration, which most Fighters don't even have a use for to begin with, and multi-class Barbarians can't use anyway. Come to think of it, it's a bit strange you can maintain a stance and rage at the same time. It's also a bit strange you can be rendered incapacitated, then "healed" and still maintain it.
Tunnel Fighter lets you have limitless Opportunity Attacks, at the cost of your Bonus Action. It also gives you a single more powerful variation of an Opportunity Attack, which can be used when the target is forced to move, or when they shift around inside your reach, because it's an untyped attack with no rules other than what this feat explicitly describes. To be fair, most of the time, you aren't going to get all of those OAs. But, with the help of your team, you will get a use for your Reaction (which can be quite rare with some DM's) and even generate quite a few free hits in the process.
Tunnel Fighter actually generates more actions, and can significantly slow down combat. It's also full of holes. (What is a stance anyway?) I would call it broken, but not in the "overpowered" meaning. Just the "this thing doesn't work right" meaning.
Conjure spells, are another kind of broken thing. In that they generate tons of actions by virtue of summoning lots of creatures to fight. They also slow down combat a bunch, which is kinda bad.
And then there are Beastmaster Rangers, which have had all kinds of threads about how they aren't actually worth what you trade into them. For an example of how things can be broken in the other direction.
