tree house build and lag screw strength

morning guys

i have decided to finally build the kids a tree house

now, i understand there is all this fancy hardware out there, but it get pricey in a hurry, and quite frankly, i feel like its overkill


this will be a relatively small platform with an even smaller "house" on it
i have climbed in the tree yet to measure the actual possibilities

the tree in question has a rather low split into three lare branches
i intend to use those three branches to build my tree house on

now, i am open to any and all advice, but the main thing i want to know, right now, is if i use 3/4 x12 inch lag bolts, will that suffice?
(and i understand that this is a vauge question, so perhaps i should ask "what is the weight bearing capacity of a 3/4 x12 lag bolt)

in essence, the enter structure will be perched on 4 of these bolts so that is kind of a big deal