So you've decided to go with drops

[Dracos]

Was playing Castlevania: Dawn of Souls recently and well, as those who have played it know, it's got a pretty heavy collect them all type setup.  In a way, it brought me right into my frustrated 'screw the damn drops'.  Largely it did this by relying on the same age old randomness.  Of course, my answers in that article don't fit here.  Well, they do actually, but it being an action game..ah, heck, it just got me to pondering the assumption "We're going to do drops and have that be where important items are kept".  Say this is still kept in there and we've got to do it this way, hell or high water.

   I'm going to say that probability is still a pretty poor way to do it.  Or rather, probability decided solely by the item rarity.  The first thing I'd say is that it should be moded in standard gameplay.  Random seed point plus 'you've killed 20 of them, you get an item'.  Yes, it's crude, but it also reflects the importance of saying that there's nothing gained gameplay wise by encouraging folks to walk in and out of a room 300 times killing the same enemy in a single strike in order to get the drop.  Yes, it expands the time the person spends on the game, but all it is doing is making the act of being a completionist charge against the overall fun had earlier.  The amount that they'll be willing to go largely based on how much fun they've had and how often they get a reward.  Yes, sometimes levels work, though after one, I think they more act as "wow, I've been doing this for how many enemies?" especially with castlevania's SotN style.  

How do you pick the mod?  Well, here you've got to take into account most importantly the rarity of enemy.  An enemy that is extremely rare does not need an extremely rare drop rate.  It's unnecessary.  Getting the farmer skeleton's soul was a 4 percent deal.  It was max rarity category.  That doesn't sound too bad, especially since you can double it to 8 percent.  Hey, that means you've got a good chance of getting it in 25 kills or so.  Fair enough...

Why is that logic wrong?  Well, there's only a single skeleton farmer in the game.  The odds of killing him more than twice a playthrough are small.  In fact, the only reason to repeatedly kill him is for the soul.  He's not a particularly good xp giver.  He drops no items.  He's not even in a particularly convenient place in the room for diving in and out and killing him.  Intended as a rare soul or not, the rate was dealt twice: Once in the actual drop rate and once in the enemy placement.  I can't help but think that these were considered separately instead of together.

 Given that there's only one, a 20 percent drop rate would've been keen since the likelihood of getting it in a given play through before you start camping would still be in the 20-25 percent range.  Putting a 'random seed starter and drop every 8 kills' would completely obliterate the possibility of repetitive killing of it 25-30 times,  while at the same time be nearly invisible, in practice, compared to a dice roll.

The idea should be that: Once the player has decided to camp an enemy, the likelihood of them getting it should be significant in a reasonably short time frame.  Once a player has begun a camping action it's only a matter of time until they get it and prolonging it only results in a chunk of extra repetitive actions instead of the game recognizing that "hey, the guy is just camping this until it drops what he's trying to get" and being set up with both mandatory limits on the time they'll need to camp and/or considerations of the general setup helps improve the game.

An alternate example is The Creature from the same game.  Here, there are three of them in the game world, you're likely to kill about six to eight per run.  It even has a powerful and useful soul... or well, it would be provided you get it fairly early.  You generally don't, which reduces its usefulness pretty fiercely, but that's a minor bit.  It's got a 1 percent drop rate.  2 percent with the soul eater ring.  So, on average, you can expect to kill 75-150 or so for a good chance of getting the soul.  In other words, ruling out the likelihood of getting it via any method but prolonged camping.  A good method?  No, because if camping is already the optimal way to get it (and in fact, the creature seems built for it, each of his spawn points being right near a door opening), then having it take tons of repetition weakens the fun value.  There is functionally no benefit in those actions being there over basing drops on a mathematically analysis of both 'rarity' of item AND 'rarity' of enemy.  Do you have one enemy of this type that's only in one room you pass through once?  Then having a tiny drop rate only encourages camping, instead of slowly and gradually getting it over the course of gameplay.  This gets really bad if a given enemy takes a ton of time to kill, such as the 13 hit final guards did.

Just for a final bit, what if it goes the other way?  You have a monster show up lots?  Well, in that case, rare item or not, having a low rate is wise.  The ghouls in this have a 1 percent rate, but as you're likely to kill 100-200 of them in a given run of the game, this isn't onerous and in fact, plays out pretty reasonably.  Could they have gone a bit lower while remaining sane?  Certainly, but in having the drop reasonable with respect to the appearance enemy in question and the value of the drop, is better than simply having it to the drop.  Using programming methods to ensure that the player can't count up to a hundred instances of killing the same enemy in a row, would simply acknowledge that 'camping', whether encouraged or not, isn't a terribly fun activity to do at length.