Query - GMing trample

[Dhjika]

When a critter uses a trample attack as the move trhough an area (and in this case I am thinking a big creature) - does having total concealment give a miss chance to be trampled - if the trampler does not know the concealed person is there, do they still trample them?

Also in the case of big trampler - as it moves trhough an area - can it choose not to trample it's friend or ally in the area of effect?

TIA

[Caderyn]

It would trample everything in the area that meets the trample size limit if it did not want to trample the ally then it should not have moved over their square, most creatures with trample are coupled with creatures of equal or greater size which cannot be trampled by them.