For now I just go ahead, put the immunity I want, cross off those who have it, then go for the other immunity gene, cross some out, then whoever does NOT have EITHER immunity gene is a good mate. I usually auto- cross out those peeps who have bad genes like crippled paw or sick peeps, as long as the sick peep has common and/or copied immunity genes as the nicheling i'm trying to breed. I WILL breed in these cases: (The first set is nicheling I want to breed)
B F , Home Home = I will breed these two.
B F , G Home = I will breed these two.
B F , F Home = I will only breed these two if desparately needed.
B F , F B = I will only breed this pair if they are the last two alive.
Have a good day!
~Iris'Sun