I came across a situation where one of my PCs were fighting against a caster that had readied booming blade for if they provoked an opportunity attack.

They decided to try and break the caster's concentration with an Attack action, but ended up missing. Being on low health, they decided to risk running away without Disengaging. The caster hit them and they dropped to exactly one hit point.

The dilemma is that if they moved like they are supposed to, they will trigger the thunder damage and drop to 0 hit points; however, they were already moving since the opportunity attack was triggered. So the question is:

Do PCs have momentum? Or are they able to stop on a dime in complete disregard for physics because they just got stabbed?


2 Answers 2


In previous editions of D&D, players would normally plot out their movement and then the DM would tell them when and if something interrupted that movement.

That is not exactly the case in 5E. In 5th edition, everyone has control over their movement unless something is forcing movement. When a character or creature moves, it is feet (spaces) at a time, and anything that might interrupt their movement stops them, and then they can choose how and if to continue movement.

This was confirmed by Jeremy Crawford on Twitter:

A target hit by an opportunity attack mid-move is in control of its movement, unless somehow compelled. #DnD

Does this mean the creature is aware that if it moves, it's going to die because of damage from Booming Blade? Perhaps not, depends on how perceptive the creature is. It DOES mean the creature just got stabbed and must now take a moment to process what happened and make a decision on how to proceed.

To farther expound on momentum and physics? It's not quite working like you might think. An entire round (everyone acting and taking a turn before the initiative resets) is 6 seconds. An opportunity attack occurs just before a creature leaves melee range. Think of this as a creature is about to move away from combat and the enemy takes a final swing at it. It's less about the person in a full run in the other direction, and more about breaking combat BEFORE it takes off into a run.

  • \$\begingroup\$ thank you very much this is exactly what I was wondering about. this extremely helpful and useful......... \(@_@)/ ~praise the sun \$\endgroup\$ Commented Jan 22, 2016 at 21:04
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    \$\begingroup\$ @namemoniker Just as an aside, most people will wait several hours to at least a few days to see if anyone else offers even better advice before selecting an answer as your preferred one. In this case I do believe I have properly answered the question but, it's just a courtesy around here. Or else you might dissuade other people from trying to give answers that might be better than mine. \$\endgroup\$
    – Airatome
    Commented Jan 22, 2016 at 21:13
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    \$\begingroup\$ sorry its just that your answer ... well answered the question. while I would be glad to read any more insights that anyone has into the subject matter your answer just seems so logical that I guess I jumped the gun on it. my sincere condolences to anyone who was planning to answer this question and did not get the chance to do so. orz \$\endgroup\$ Commented Jan 22, 2016 at 21:27
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    \$\begingroup\$ It is possible to unaccept an answer to accept a different one, but accepting an answer does have a tendency of discouraging other answerers from potentially giving a better answer. \$\endgroup\$
    – xanderh
    Commented Jan 24, 2016 at 10:26

No, there is nothing in the rules that supports this claim.

The rules for Opportunity Attacks does not contain any specification in stopping a creature after being hit by an OA, except when there is a game feature that explicitly tells us so.

Moreover, the Sage Advice Compendium clarifies this:

If I use the Ready action to deal damage to someone who’s moving, do I deny the target the rest of its movement?

Dealing damage to a moving target doesn’t halt its movement, unless the damage is accompanied by an ability that stops movement. Things like the Sentinel feat give you such an ability. Reducing a moving creature to 0 hit points is also usually an effective way to stop it!


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