Are missions at least partially random in their success, or am I understanding them improperly?

I'm putting a level 50 pet (which is *twice* the level it asks for) into a very hard mission, who's wearing purples and oranges. The mission, let's say, is Ox at Heart, which calls for Strength.. so, I'll make sure my pet is Strength based, but I'm failing almost every mission I do. What am I doing wrong?

Isn't that a Very Hard mission?
I suggest at least 275+ in the asked stats, but I was sure
was Dextery dear, not Strengh, because the pet I sent in
that one is ONLY in Dex... owo"

EDIT : And lvls only affect at which you can start sending
a pet into that mission~ Even if higher, doesn't affect
apart from that you can have more Stats points into that
said "Dex" asked or anything~ owo"

EDIT 2 : And even if it have high stats, doesn't mean it'll
always success "fully", my Koza have 295 and just did a
"okay" success in that mission... o.e"
So finally more close to 300+ dex if you want it to be
better I guess... o.e"

Ox At Heart is indeed a Strength mission- I triple checked before putting him in yet again.

The pet in question is http://www.sylestia.com/view/pets/?petid=1100

Who has a strength of 316. =)

Oh really? Then it's weird because me I always have
sent my Dex pet, well my guess on stats still stay~ :3
300+ should be enough to be able to give Success
all the time in my mind~ :3

But I find it weird, because it's a Dex mission to me?
Never been a Str one... o.o" Either there's a bug,
either there's problem~ P=
That could explain WHY you're failing it?... o.o
Because in my mind, if your pet's 316, it should at
least do a good Success or a OK Success... o.e"

EDIT : Better wait on Krin or Faiona to light us on this,
because I believe it's a Dex mission, since I sent Koza
on it a while ago~ owo"

If it's a very hard mission, it's likely you may need 350+ on your stats to succeed.

I've noticed, since the missions system was revamped, it's best to have almost every level-up point invested in the stat in question in order to be able to succeed, or at least have some REALLY good gear that boosts the particular stat by a good deal (in addition to heavy focus on said stat with level-up points).

Ack! You're totally right- I kept thinking Wrecking Ball and typing out Ox. =)

And.. that makes sense, if there's a revamp.. But there's only so much you can do here, just now, and having a level 50 do these, at the "area level cap" that it is fail was frustrating.. But if it's because they're about to open up a whole 'nother area, I suppose that makes more sense.

Yeah, unfortunately it seems that "Level" is more indicative of how many level-up points (equivalent) should be invested in that stat (ie: with level-up points and/or gear combination).

Also: They were supposed to be opening up the new area here on the 7th, but it was pushed back due to the amount of content still needing coding and everything else coming out that day. So that means it should be coming soon enough, within the next few weeks, so there's that, too. :3