# When does a runner regain his Dexterity bonus to AC?

The combat action run says

You can run as a full-round action. (If you do, you do not also get a 5-foot step.) When you run, you can move up to four times your speed in a straight line (or three times your speed if you’re in heavy armor). You lose any Dexterity bonus to AC unless you have the Run feat. (Player's Handbook 144)

(Links mine.) Unlike the special attack charge that specifically says that a creature that charges suffers "a −2 penalty to [its] AC until the start of [its] next turn" (PH 155), a creature that takes the action run seems to be lose its Dexterity bonus to Armor Class only while running on its own turn, regaining its Dexterity bonus to Armor Class upon its turn ending—that is, when it stops running.

However, my players were shocked during a recent session when the advanced mama phargion (Miniatures Handbook 66) took the action run on her turn and I said that on their turnsafter mama phargion had taken her turn but before mama phargion had taken her next turn—that mama phargion was not losing her Dexterity bonus to Armor Class against the PCs' attacks.

My players said that their PCs should be making their attacks against a mama phargion that had lost her Dexterity bonus to AC because she ran on her turn and she hasn't yet started her next turn. I said for that to be the case, either the action run must have an exception like the special attack charge or the action run must take not a full-round action to perform but, instead, a 1-round action to perform (like casting a spell with a 1-round casting time). (This latter option would also mean the runner wouldn't reach its destination until right before its next turn—as if combat weren't complicated enough already!)

Did I rule correctly? Does a creature that takes the action run only lose its Dexterity bonus to Armor Class during its own turn, or does a creature that takes the action run lose its Dexterity bonus to Armor Class until the start of its next turn? Or is there even more to this than I realize?

• I don't know if you are still interested. There is "If you spend the entire round running, you can move quadruple your speed" phrase in combat section. It at least hints that run lasts longer then your turn. I'm not sure I may compose an answer based on it, just thought it may be helpful. – annoying imp Mar 1 '19 at 7:01
• @annoyingimp You can compose that answer, but I think it'd look a lot like this one, and I suspect my comments on it would be similar. :-) – Hey I Can Chan Mar 1 '19 at 7:08

You ruled correctly: when using the Run action, a creature loses their Dex bonus to AC only during their turn. The Charge action, Power Attack feat, Combat Expertise feat, Cleave feat, and other similar effects all explicitly state "... until the beginning of your next turn." The fact that Run does not indicates that the penalty does not continue past the action that granted it.

There was another, similar question that was posted last year and the top-rated answer came to the same conclusion.

There also seems to be some confusion as to just how long a "full-round action" takes to complete. Looking under "Cast a Spell" type of full round action shows the following:

A spell that takes 1 round to cast is a full-round action. It comes into effect just before the beginning of your turn in the round after you began casting the spell.

...

Sorcerers and bards must take more time to cast a metamagic spell (one enhanced by a metamagic feat) than a regular spell. If a spell’s normal casting time is 1 standard action, casting a metamagic version of the spell is a full-round action for a sorcerer or bard. Note that this isn’t the same as a spell with a 1-round casting timethe spell takes effect in the same round that you begin casting. [Emphasis added]

This illustrates that full-round actions, such as the Run action, happen only during your turn. This means that a running creature only loses their Dex bonus to AC during their turn since the action doesn't extend past that.

• I see the evidence, but this effectively means that the loss of Dex bonus to AC concerns only attacks of opportunity, readied actions or immediate actions of opponents. In other words: In most cases it does not matter. What is the point of a penalty that can mostly be ignored? This seems like an editorial mistake to me. – Giorin Oct 3 '17 at 21:58

The rule for running reads to me that the creature or player initiating the run action would lose their dexterity modifier for THEIR turn. That being said it does not leave the players without any options for attacking the creature flat footed.

I would rule that, in the future, an intuitive player may take the opportunity of a severely hurt creature or NPC to put themselves in line for an attack of opportunity, or ready an attack against the creature if they "see them make a run for it". If there were any melee characters in range of the creature when it ran they should have clearly made an AOO against it at its flat footed AC as it left the threatened space adjacent to the attacking character.

If someone asked "Well how do I know its hurt if it's HP is out of game knowledge?", valid, until you reference knowledge skills such as Nature, Planar, Dungeoneering, Etc. (Which are completely underused in past experience) to fill the gap. Any player can make a check at the start of battle (set a DC) and be able to glean information about the creature each turn if they choose to. It also falls on the DM to use trigger statements during combat "The creature takes your blow with recoil and labored breath, it is clear this fight will not last much longer." (a little on the nose but you get the point).

My thoughts anyway. I believe you ruled correctly and it should be a lesson in placement and planning on the parties part from here on it to prevent run-aways.

• Welcome to the site. Take the tour. At the table I explained that, for example, a ready action with the trigger If she runs by me with the action I stab her would allow possibly two attacks against mama's flat-footed AC (one normally and another for provoking an attack of opportunity), but players seemed nonplussed. I was hoping (probably vainly) for a published example or an advice column or something, and I'm not sure your third 'graph helps (it seems to drift from the topic a bit), but, nonetheless, thank you for sharing your insight and for helping strangers and enjoy your stay. – Hey I Can Chan Apr 22 '17 at 17:52

This seems to be a problem among a few of the forums, don't think "Full-Round Action" is defined very explicitly in RAW.

A full-round action requires an entire round to complete.

In my personal interpretation, a Full-Round Action is something that is ongoing until the beginning of the next turn (hence taking an entire round to complete, not just mama's turn). A full attack action lasts six seconds in-game, but is resolved at the end of the turn IRL.

Personally, I would rule that mama phargion would be flat-footed until her next turn came around, due to that her spending a full-round action running would mean that she's running until the start of her next turn.

• I do think you need a little more detail here describing the difference between full-round actions and 1-round actions (namely, full-round actions are resolved during the turn they were started, but 1-round actions don’t resolve until the beginning of the following turn). I think you’re right that on some narrative level full-round actions do represent actions taking place over an entire round (not just a turn), but the timing of resolution is still important (can’t move out from under a full-attack, for example). – KRyan Apr 27 '17 at 17:38
• Can this answer resolve why a charge (that also a full-round action) specifically notes how long the penalty from taking the charge action persists, but the run action doesn't mention how long its penalty persists, yet both actions penalties are, by this answer, supposed to persist for the same duration? – Hey I Can Chan Apr 27 '17 at 18:01
• KRyan, I get the feeling that resolving a full-round action vs. resolving a 1-round action has to do more with balance than with narrative. Playing out in real time a full-attack action that an enemy steps out of after the first attack would feel kinda cheap, and leave the player swinging at air for the rest of his "programmed" full round's worth of actions. – Lum Apr 28 '17 at 20:02
• As for why a charge specifically notes how long the penalty lasts, I don't know why charge mentions it but Run doesn't. I'd think that the penalty lasts until completion of the action, which for Run (as a full-round action) would complete at the beginning of the player's next turn. I think it's the ambiguity with the resolution of it that is why they included a definite end time for the penalty to charge, because charging is resolved in the turn that the charge is made, but it's supposed to take about 6-seconds of real time. – Lum Apr 28 '17 at 20:04
• Just so I make sure I'm not misunderstanding, is this answer saying that a full-round action and a 1-round action are one and the same? (I apologize if I am misunderstanding and oversimplifying if that's not what the answer's saying, but I am trying to put this in simpler, playable terms.) – Hey I Can Chan Apr 28 '17 at 20:14