Loot is one of inherent parts of RPGs. One of important questions is: When does it drop? How rare is it?
Rarity of items and associated prestige is one of driving factors for players. For developer, inequality of Loot is important as well because it helps community as player will be more depended on interacting with others rather than just grinding himself when he wants to obtain something specific, making Trading part of game.
In order to create rare item, obvious solution is to make it so that it drops infrequently. Is it actually best solution?
Lets have scenario: Players want to obtain ‘Demonic essences’, a highly prized commodity. This essence is supposed to be infrequent and its usage is supposed to have important effect, something that would create demand for it – say, ‘Essence’ is used to grant player long lasting powerful buff. Ideal candidate for semi-rare item, so we assign it low droprate of 1%.
Player who recieves this item basically wins jackpot. However we run into two problems:
1) Player being very lucky and getting this item from first demon that he kills. This is not problem for player, but it creates precedent for him and should he share his experience (and he most likely will) it creates measuring yardstick for other players. Several lucky players flaunting their good drop rate skew perception and anyone less lucky heel he was cheated even if he is too above expected average droprate.
2) Player being very unlucky. When killing one thousand demons will not yield drop (and when confronted with player 1) ) he is getting rightfully pissed. Now, ideally he should resort to trading with lucky players, but chances are, he massacred Demons so that he himself has good to trade with. Now, there are ways how to lessen this: ‘Consolation price’ drops; steady amount of various not-so-desirable loot that he can still use, but he too will share his stories and more voices will join up. And usually, some kind of weird player behavior will result (“I killed Demon with Demonslayer sword and it did not drop essence in 1000 kills, so i switched to Angelslaying sword and had drop immediately.”)
As can be seen, ‘real’ probabilities just do not work well because while results add up in large numbers, players only see fraction of them and can be subconsciously selective, making them see all kinds of patterns.
There are ways how to solve this:
1) Guaranteed drop. When every hundreth Demon should drop essence, well, lets keep counter and make ‘right one’ drop it. This is quite awfull because total determinism is not really that much fun, and after a while players become correctly wondering why are they supposed to bother with killing 99 other demons.
2) Cumulative drop rate. Simply, every time item fails to drop, chance of it dropping increases eventually making drop 100% sure. This can give easy upper limit on number of Demons slaughtered. This guarantees drop after certain amount of attempts. However, individual kills that do not result in drop are still unsatisfactory.
3) Split drop rate.
Idea is simple: One ‘drop’ is split to ‘subdrops’ that can be combined. Individual subdrops can have much higher droprate, making each kill more satisfying.
Not only that, it also creates more market opportunities – being able to ‘argument’ someones droprate by selling him part of Item, and thus lowering amount of time she needs to spend obtaining such item.
And when we go further, this allows easy scaling of drops per difficulty. Item can drop more frequently but that does not give clear feedback. On the other hand, it is easy for player to grasp that Demon Lords drop several components at once or that they drop component on every kill compared to normal demons who drop less frequently.
