Mhm the reactions are all triggered, would be insane when someone could interrupt the triggering action so that other reactions are then wasted.

@DmMacniel What about the second one. Does Topple Foe re-prone an enemy hit with Reactive Strike since Reactive strike is triggered by standing up and Topple foe is triggered by being hit?

You only have one reaction per turn. So if an ally (which does excludes you) Reactive Strikes a prone enemy that tries to Stand (which is an action with the Move trait) and succeeds, you can then react to that successful strike to Topple Foe to Trip them thus causing them to get the prone condition again. So yeah in a duo this would be possible, alone not.

>[Reactions](https://2e.aonprd.com/Rules.aspx?ID=2023): These actions can be used even when it's not your turn. You only get one reaction per encounter round, and you can use it **only when its specific trigger is fulfilled**. Often, the trigger is another creature's action. >[Stay Down!](https://2e.aonprd.com/Feats.aspx?ID=4978) > >Trigger: A prone foe within your reach **Stands** > >You have ways of keeping your foes down. Attempt an Athletics check against the triggering foe’s Fortitude DC. On a success, the action is disrupted, causing the creature to **remain prone**. On a critical success, the creature also can’t Stand until its next turn. I think the trigger for Stay Down! should be *attempts to stand*, especially if you look at other disrupting reactions like [Disruptive Stare](https://2e.aonprd.com/Feats.aspx?ID=3995), [Reactive Interference](https://2e.aonprd.com/Feats.aspx?ID=4972), or [Miraculous Intervention](https://2e.aonprd.com/Feats.aspx?ID=3640). Reactions trigger after the action is fulfilled, so the enemy can't remain prone if they're already standing. So I'd say Stay Down denies anyone else a reactive strike. [Topple Foe](https://2e.aonprd.com/Feats.aspx?ID=6360) would have to trigger after a reactive strike, so that works fine.

So very often, these types of questions remain fully mired in the realm of naked mechanics, but I find it helpful to imagine what's actually happening in the fiction. The mechanics are there to aid the fiction at the table, after all. So, what's taking place during Stay Down!? How is the creature keeping the target down? To me, this has real "stomp" energy, where the user is putting their foot on the target's back, or dropping a knee on them, or something, while yelling at them to stay down. The target tries to get up, but is forced back down to the ground before they can really move -- after all, if the prone creature can get up into a plank position, or up onto their hands and knees, it becomes significantly harder to force them back into a prone position. That is to say, it happens very early. Reactive Strike, on the other hand, is about looking for openings to strike, where the target has let their guard slip (or abandoned it altogether). This is why it applies when the target is trying to stand -- it's very hard to defend yourself from a determined attacker when you're transitioning from lying prone to getting into almost any other position. But when the first creature uses Stay Down, they are functionally putting themselves between the target and anyone else who might want to strike. An ally might not want to take the chance in this situation, particularly since the fiction is not "attacking someone who's being held down", but "attacking at the same time that your ally is getting in the way". Topple Foe, on the other hand, is entirely about taking advantage of a distracted or staggered target and trying to sweep or tackle them to the ground. And unlike Stay Down! and Reactive Strike in the first example, it doesn't even have the same mechanical trigger as the reaction you're trying to pair it with. This is just a pure tag team shine spot.