Well, not just geese but 'doobers' of all kinds, collection items, resource items on the trail, even higher amounts of the basic stuff like XP, food and coins sometimes.
Well, the answer is simple, and it's dice. Very large dice, but dice nonetheless, albeit the kind an avid Dungeons and Dragons fan might recognise instead of your average Snakes and Ladders player (unless they suggest you roll a dice, times it by three, add your Luck plus your Stamina and measure it against the Snake's Strength to see if you slide down...).
Picture this... a one hundred sided dice in digital form inside the game. Every time you harvest, tend or collect a bonus the game rolls that dice to see if you've "won" by matching that with the chances of you winning.
Take for example those pesky Geese and Pack Mules in the Pass. Every time you do something with your hunter there's a 10 in 100 chance of a Goose and a 40 in 100 chance of a Goat.
So what does that really mean? Well, the one hundred sided dice is rolled, on 10 of its sides is the word "Goose", on 40 of its sides is the word "Goat" and the remaining 50 are blank.
If the roll goes your way, then the item will pop out. If it doesn't, a blank side is uppermost and you get nada.
This also explains why, although we can give you chances, they sometimes don't seem right. A regular exchange on the page goes something like this:"The Geese are only a 1 in 10 chance."
"But I've done 10 and didn't get one..."
The fact is every single action we do is a whole new roll of the dice. If you have one nearby lets try an experiment, pick up a dice and roll it six times.
Despite the fact the chances each roll are 1 in 6 of getting a certain number I'm going to bet that for the majority of you you didn't roll the numbers one-six in any order during those six rolls, that's where chaos theory, entropy and pure goshdarned LUCK comes into it. (If you rolled one to six IN ORDER... I'd try the lottery this weekend if I were you...)
So there it is, folks can come up with personal beliefs as to what pops the resource items, or theories they're only offered at certain times or certain missions... but to be honest it's mostly our mind playing tricks on us.
To put it bluntly, everything that pops out randomly in the game is just a product of gambling...
