If you're here I'm sure you've already seen the guides on quick ways to make zenny. This guide should teach you some underlying methods for finding and evaluating zenny farming outside of instances. To begin:
Let's talk about how Ragnarok online monster spawning system works.
This is Prontera Sewer:
You would never farm this map because the monsters here have cheap, generally worthless drops, the MVP being the only exception. We're going to use it as n example because it has three relatively easy to perceive layers: outer, middle and inner. Lets look at what mobs spawn here:
This is the mob list taken from ratemyserver.net. Take note of the monster quantity and spawn rate. Thief bug eggs, for example, will spawn once every 5 seconds until 10 exist on the map. Not all maps have this delay in monsters spawn until hitting the mob cap. In fact, for the most part, you can forget about the spawn rate and assume that the amount of mobs on a map will remain at the cap at any given time, as indicated by the @whereis command. MVP's and sometimes mini-bosses are the exception to this.
What's worth noting is that mobs will be spawned uniformly across the entire map regardless of where active mobs exist at the time of an individual mobs death. There are exceptions, again, but for the most part this means that whenever you kill a mob on one section of the map they will be respawned randomly, but uniformly, across the entire map. This can be used to your advantage.
Let's say you are the first person to enter this map following a server restart. This map will be cleanly populated with whatever mobs are set to spawn there. They will be distributed across the map randomly but relatively even spread. Let's say you start from the top right corner and move in a circle about the outermost layer of the map (as above.) All the mobs that you killed will be redistributed across the entire map which means the mob density will have increased on the sections you haven't touched but will be sparser on the section you just cleared.
Move into the second layer and repeat the process. Again, you'll have cleared out a section of the map, increasing mob density in the other two sections and reducing it in the section you are on.
Finish up by clearing out the inner layer of the map. You should visibly notice an increase on mob density at this point. So you've now gone from an equally populated map to an unevenly populated map split into sections. This works for you because you can now repeat the process with higher mob density in the other two areas. Essentially, by doing this you've increased your farming rate by about 30% since you taken 100% of the monsters and roughly funneled them into 2/3s of the map, which you will be clearing to maintain that 2/3s in the sections you kill the mobs on. If you've ever done a board or booster quest and found all of a mob you're supposed to hunt in one small, isolated corner of the map where players tend not to go, the spawning mechanics illustrated above are why that happened.
Also note, you should levy your characters capability to make best use of your time. It doesn't matter if a mob drops 10 million zenny worth of items every kill if it takes you half an hour to kill it. You'd be better off farming a map with a higher population and cheaper drop that you can kill effortlessly than working on killing a mob that may drop something expensive. In the end though, that's a choice you have to make.
Moving on, let's talk about inventory management.
You probably already know this, but your inventory is limited based on not only weight but quantity. Weight doesn't really bother most people now that the Gym pass is a thing but the total number of individual items you can have can impact your farming. In the above image you can see I have 70/200 unique items. It's easy to fill that when farming. Let's look at Amicitia 2.
This is an Amicitia mob. As with most mobs, a majority of the drops are relatively useless outside of specific needs (quests, crafting, whatever.) But, the etel dust is certainly valuable and fortified equipment sells for somewhere in the are of 35000 zenny a piece.
Since every mob in amicitia has their own example of worthless drops that wouldn't amount to that much even with a full stack, it's a waste of time and money to pick up those drops. Fill your inventory with stacks worth holding for sale (or personal use.) Though it's not always the case, you can generally accomplish this with lowering your autoloot percentage cutoff. If not, you can always use @alootid to pick up specific drops. I think there's also a command in the suggestions section for rejecting specific drops so that may be a thing as well at some point.
As an aside, note that the above map is rather large so increasing mob density would still work but it would be less effective due to the amount of time it would take you to make it happen.
Finally, let's take a look at drop rate. As can be seen in the above Mutant Chimera Napeo's drop list, the base drop rate for valuable items is generally low. However there are ways to increase this.
First and foremost:
Gum. Percentage multipler increase of drop rates. Multiplies with whatever other drop rate increases you have. Which include:
Monster Hunter Coin Equipment.
These can be purchased from Lucy found here in the image below. Use @go special and walk right for quick access.
And the most significant boost to drop rate you can achieve comes from making a booster character. Leveling from 1 to 230 at a set 1x rate using only a limited set of exp boosting consumables will net you a permanent 50% drop rate as is seen in the above picture on the right hand side of screen (Circled.)
To begin your booster character quest, go to eden headquarters and talk to the npc just inside the entrance, slightly up and to the right (see image below.) For the record, I recommend looking at other guides and knowing what you're getting into before starting a booster char.
if you wear all of the above equipment and use the normal bubble gum on a booster char, your drop rate will more than double for any given item. HE will more than triple it.
All that said and done, many good farming spots have already been pointed out in other guides so I'll leave that to them and I'll leave it to you to figure out your own. I can currently farm ~60 million zenny an hour using the above methods without farming instances. I've also only just come back to Shining Moon so I'm assuming new spots are available and other players are capable of outpacing me.
Final notes:
If you think you've found a good spot to farm, test it out and see if your income over half an hour would warrant the use of bubble gum. If the increase drop rate would recoup and exceed your costs for buying the gum (4 moon coins for 1 gum in cash shop = ~ 3.6 million zenny @vending rates,) give it a shot. I've found basic bubble gum to more than double my income over said half hour for items with a base drop rate of 5-10%. Items with drop rates higher than that normally aren't valuable enough to farm once you're leveled and geared.
Look through @vending for people buying random items. They won't be the best price but they're there and available for sale at any given time; until the vendor logs back in I guess.
I can't say it's always the case but teleporting around the map to farm can be counterproductive. Porting around will clear out random parts of the map which will leave you randomly coming across lower, standard or high density mob concentrations. You're essentially randomizing you overall farming rate rather than having a standard start followed by a consistent, greater than normal farming rate.
Good luck. If anything here is wrong or off please feel free to comment. Hopefully I'm not painfully ignorant of anything that would make this guide obsolete but we'll see I suppose.
