I just joined earlier today and I was wondering, are uncommon pets harder (and thus have a higher failure rate) than common ones when attempting to capture?

yes, depending of the rarity (stars colors) a pet can be catch with a different trap if you try to catch a uncomun pet with a lesser trap it have less chance to catch then if you use a better trap. More the wild pet have traits more he is difficult to capture. ^-^

ps : 2 caries = 1 visible

Ah, thank you so much!