Then they used the wrong term, and that I take the word at its meaning ain't my problem.
"Knock over" in reality is a different action than "trip", requiring different movements and different abilities (strength and size instead of dexterity), and thus if it's to be mechanically represented it needs its own mechanics (I'd batch them in with "push" and similar). Sticking my foot out and tripping someone requires dexterity and a bit of stealth, while bodychecking someone to the ground just takes sheer brute force and bulk.
"Flip" or "throw" would be in the purview of Monks and others trained in such things (though a Monk ain't gonna judo-throw a Gelatinous Cube no matter how hard she tries!). "Cause to stumble" is broader and can cover many things, including telekinesing a flagstone up off the path while hiding in the bushes.
All of these could have been batched together into a "stagger" mechanic, under which would be listed examples of all the above except flip or throw, which are under a different category of martial moves. Whether the victim was knocked prone would be rolled for separately.
Its been a while since I was caught up in this thread but this stuck out to me.
I just wanted to clarify that while 4e has a prone condition and a number of powers that knock an opponent prone, it does not have a mechanically defined trip game mechanic.
The 4e FAQ was discussing whether a cube can be knocked prone. The blogger was using trip as his 4e example, but 4e does not itself use trip.
"Can a gelatinous cube be knocked prone? In situations like this, DMs are encouraged to change the flavor of what is happening without changing the actual rules governing the situation. For example, the ooze could be so disoriented by the blow that it suffers the same disadvantages as if it had been knocked prone until it spends a move action to stand up effectively shaking off the condition"
The term trip is used twice in the 4e PH, but only narratively.
In a level 13 Fighter power the flavor text description is "You trip your enemies, knocking them back. As they recover, you shift to a more advantageous position."
Mechanically this attack hits them for damage and pushes them and the fighter follows up with movement to follow them, more push and movement with a spear type weapon. No knocking them down prone at all though.
There is also a level 13 rogue attack power of unbalancing attack.
"Ducking and weaving, you land a decisive blow that staggers your foe and sets it up for a tripping attack."
"Hit: 3[W] + Dexterity modifier damage, and the target cannot shift until the end of your next turn. If the target provokes an opportunity attack from you before the start of your next turn, you gain a bonus to the attack roll and damage roll with the opportunity attack equal to your Strength modifier, and you knock the target prone on a hit."
The narrative parts are only in the power section labelled flavor text and the explanation of powers explicitly says these are examples and can be narratively changed by the player.
"A power’s flavor text helps you understand what happens when you use a power and how you might describe it when you use it. You can alter this description as you like, to fit your own idea of what your power looks like."
