The combat rules are abstract. The power rules ought not to be unilaterally messed with for arbitrary reasons.
Bonus points if you read all of this [MENTION=73683]Dannager[/MENTION]
I have read through everything up to this point and just wanted to ask you, what about cases where it is not arbitrary? Cases where the decision is not random, or simply based on a whim - but rather where the DM put some thought ahead of time and said, "quick note to self... this guy can't be made prone".
I ask this with total respect, and not looking for an argument - I simply want to clarify as you seem to refer to "arbitrary" reasons being unreasonable... so I'm curious about pre-determined (non arbitrary) reasons (and if you referenced those already somewhere, I apologize - been reading this thread for a while now and things are getting blurry).
In other words, would you be cool with the situation if the DM said, "Well, it was something I decided ahead of time", or do you need something more - perhaps the DM telling you in advance, before the game started? Where is the line, essentially?
I feel like (and I could be wrong) you
would be okay with a DM modifying a creature BEFORE the game, making it impossible to knock it prone (as in this case it would not be an arbitrary change) - after all, monster modding/reskinning is a big part of the DM's toolbox. However, a lot of DM's (myself included) do a lot on the fly and some decisions such as these come right to our mind in the midst of the game.
The problem here is that if you
are allowing it when it is planned, but
not allowing it on the fly, then I feel like it becomes a gotcha game - where it is now the player vs the DM - "no way DM, you didn't say it before we starting playing" etc. Sometimes the player vs DM is a good/fun/intentional thing (see
Fourthcore), but it has never been so in my case, with any of my players, ever for over 20 years now.
In fact, if I told my players "I will make no snap decisions on powers during play - rather, I will let you know ahead of time the changes I am making to monsters" my players (any/all of them, ever) would cock an eyebrow and ask, "why not?".
I'm going to quickly touch on this specific comment about power rules and that they "
ought not to be unilaterally messed with for arbitrary reasons". I get the feeling here that your argument stands on the idea that, "the power says it does X, so you can't change it... it's in the book". The problem for me is that in the DMG, page 4 under "How to be a DM" it says...
"The DM's goal is to make success taste it's sweetest by presenting challenges that are just hard enough that the other players have to work to overcome them, but not so hard that they leave all the characters dead"
...this is also in the book. And in fact, it doesn't say anywhere that powers can't be tweaked. In fact, nothing is locked down as far as rules go. There is more to be said about the freedoms a DM does have than there is anything about what can't be changed by anyone.
With that in mind, remember that often times, the balance they talk about there (between too hard and too easy) can not fully be determined until you are in the midst of the battle. Sometimes what you think will be easy turns out to be very difficult for the players, and the other way around. The XP budget helps here (I'm speaking of 4e specifically here) but there are too many variables sometimes to know for sure. A DM needs to be able to manage the balance during the challenge. In some cases, the DM can achieve this by tweaking powers, or the results of them, like previous examples of the ooze not being knocked prone. And in that case to me it's not all that arbitrary - at least there is an argument to be made there. To me, arbitrary in this case would be rolling a % change for your power to fail "just because", or just saying "no" every once in a while for no other reason than to hear themselves say it - I hardly think these are reasons behind Wik's tweaking (I assume anyway).
Here's a quick question related to this as well... what if the DM had said, "Ok, he is knocked prone. In fact, he's also... I don't know... blinded for smacking his head on the ground?... 2 rounds blinded, save ends" - is this change acceptable or arbitrary, and as such something you would prefer left out?
To give you a quick story, I never stepped out of a D&D game as a player for any reason other than a scheduling conflict until last year. Why? The DM did not make the game challenging enough. He upped encounters here and there, and did what he could, but our group was so well organized (nothing to do with me) that it continued to steamroll everything. This game was no longer fun for me and after our 18th game of the campaign, I finally stepped away - it just wasn't challenging enough. I told him previously, "I'm just not invested in my character because there is no reason to believe we will ever be challenged - there is no fear of death here". Of course, that doesn't mean you have to "break" the rules to make the game challenging, but I would have certainly welcomed it if he had.
Anyway, again, I'm not trying to call you out and pin you to anything specific - it's just a genuine question is all, one I kept asking myself as I was reading through the middle part of this thread. If this sounds like I am trying to be an arse, then we'll blame it on me being very tired at the moment (I hope the post makes sense)
--- EDIT ---
One quick addition since there has been no response after this yet (I added a question a few paragraphs up)