Hriston
Dungeon Master of Middle-earth (He/him)
Show me that rule.
“On your turn, you can... take one action.”
Show me that rule, too.
“you can make a special melee attack to shove a creature, either to knock it prone or push it away from you.” The text says, “Using the Attack action,” but shoving a creature using a bonus action is resolved identically. I.e., "Instead of making an attack roll, you make a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use). You succeed automatically if the target is incapacitated. If you succeed, you either knock the target prone or push it 5 feet away from you."
And this is just blatantly false. You know the moment you use something whether it's an action or a bonus action. The ability you use tells you straight out. Despite your claims, there is no Shrodinger's action in 5e.
I'm not sure what you mean by "use something". In the game, players describe what they want their characters to do, not what game-feature they use. They can, but it isn't required. You're assuming your preferred play-style is mandated by the rules, which isn't the case.
What is the case is that for his/her character to shove a creature, all a player needs to do is describe his/her character shoving a creature. It's the DM's job to work out which game-elements come into play, and to resolve a shove, all that needs to happen is a contested roll.
This is just sophistry. You don't declare that you are going to use an action in the game at some point during the turn. I'll go Yoda on you. Use or use not, there is no declare.
Look, you're playing games with semantics. You said, "there is no such thing as declaring an action," and that just isn't so. Step 2 of the basic pattern of play, the players' entire third of the conversation, is declaring actions for their characters. "The players describe what they want to do." That's what an action-declaration is. In the case of shoving a creature, a player might say, "I move around the orc so the pit is behind it and try to push it into the pit." Then it's the DM's job to ask the player for a STR (Athletics) check, roll the orc's ability check to contest it, and narrate the result.
This is not possible by RAW. The Rules as Written tell you what type of action you are taking in the instant you take it. The moment the PC takes a shove, it is either the action or the bonus action. Either you take it as a Bonus Action, in which case the trigger already has to have happened, or you take it as part of your Attack action, in which case you must say that as soon as you take it. There is no limbo state that the shove waits in to see what it will become.
Edit: I left out Reactions since they are not a part of this discussion. I added it in, because many people here have problems with context and/or will seize on the omission as an evasion.
What rule requires you to say whether you shove a creature as an action or a bonus action? I don't think there is one. All that's required of the player is to engage with the fiction and describe what fictional actions his/her character is taking. Again, you seem to be assuming your preferred play-style is mandated somewhere in the rules, but I don't think it is.
1. Magic Weapon: Is this contingent on something occurring later in the round? Yes.
1. Shove: Is this contingent on something occurring later in the round? Yes.
2. Magic weapon: Am I using the ability before the trigger happens? Yes.
2. Shove. Are you using the ability before the trigger happens? Yes.
3. Is my wizard being knocked out before the trigger occurs? Yes.
3. Is your fighter being knocked out before the trigger occurs? Yes.
4. Am I then re-writing reality so that the trigger never needed to happen and an action was taken to provide the effect? Yes.
4. Are you then re-writing reality so that the trigger never needed to happen and an action was taken to provide the effect? Yes.
I'm not seeing any difference in the steps taken between the two. The reasoning for both examples is the same. That one is an action and the other a bonus action is not relevant. Both can be taken at any point during the turn. If you are having problems with my wizard example, you really should take a closer look at what you are claiming.
Shoving a creature isn't contingent on anything occurring later in the round. As long as the creature is no more than one size larger than you and within your reach, you can describe your character trying to shove it when it's your turn.