Okay before you dismiss this as just another lame game pitch, think about it.
What does Super Smash Bros Melee got going for it?
Characters
Levels
unlockables
Multiplayer

This is how it would work. Scince im pretty sure you can copyright only characters, not a battle style it would be alright to use the % of being knocked out. Now this may sound lame, but face it SSBM pretty much figured out the best arena battle system.

For characters you have the base monsters
Golem, mocchi, suezo, durahan ect.
Youd start with 10. the more tournaments you play the more characters you unlock. Up to tigers, psi-rollers even.
For alternate costumes you use sub breeds. Tiger/Dragon, Durahan/Golem.
At least 6 sub breeds of each monster, this is no problem considering the MR2 combining. Secret costumes can be the ??? breeds, like Gold Suezo or Blue Pheonix.

Unlockables would be the Cards, or Encyclopedia pages you get by either the Tournaments or the Lottery thing like in SSBM. think about it over 400 cards could be found.

Levels wouldnt be a problem. Kawrea, The farm, Torbles, the Tournament arenas themselves.
It all works out perfect.

I forgot to talk about the tourneys themselves.
youd have E through S class difficulty. Beating one tourney with a character would unlock its secret sub breed.

As for the battles themselves, Dragons and Golems would be the heavy weight hitters, pixies would be the light fighters, mocci and tiger the medium weight well balanced ones.
Moves arent a problem, theres enough variety in the MR series to easily carry over the ideas.
Mochis roll would be Forward + Square.

And think how much better it would be using the PS/Ps2 controller, the best controller ever designed.

Go ahead, write it, If you don't get sued, I'll buy it. :)

I haven't played hop-a-bout. But this kinda takes away from what monster rancher is, doesn't it?

Don't get me wrong, if there are two things I hope they have in MR4, its Battle Royals and Tag Team matches (I think this one is possible with some of the shots I've seen.)

and don't be nervious about posting ideas, just don't expect them to be likely, or even liked. People just have different tastes.

Well hop-a-bout was pretty popular (by MR standards) and Battle cards is a succesful (relativly)"spin off" i guess you would call it. it would be just another leap into a different Genre

and i wasnt nervous, its just a lot of times when people post ideas it isnt thought out very well and basically consists of
"OMG they shuld mak a game were dey FIGHT OMG!!1"

Not that that happens here a whole lot, it just has to be thought out.

Yeah after seeing pokemon in SSB and SSBM, you'd think it'd be a great platform for mr2, but it was a nintendo idea, so THEY surely wouldn't make something like it.

But then you lose the concept of it being a ranching simulation (Which made MR what it is today) and becomes a fighter. I'd rather have it as a ranching simulation.

It could have both. Normal ranching with the fighting thing as a mini game or something(a very large one).

I think adding a SSBM like mini-game would be a bit
complicated. You would have to chose powers, monsters,
sub-breeds, make unlockables and their costumes, and you
would have to find new comtrols for things like jumping
and ducking. I don't think monster rancher would do that.
They might have gone a bit more towards the action genre,
but I don't think they'll go towards SSMB.

Well the problem is they need to expand the MR universe, and get it out of its niche its in.
Hop a Bout was arguably a breakout game, that was pretty decent for what it was.

So maybe the next step is expanding it into a fighter. Not a real Soul Calibur fighter i guess, but the more stategy/moves/character kind of Super Smash Brothers. The formula works so well.

IMO, I think that if they made it into something like The Unholy War (great love it or hate it type game!), then it would be cool!

Err... expand the MR universe and get it out of the niche it's in? Why do they need to do that?

It is the only game in its niche, after all.