Skull cavern is a dungeon you unlock after completing the mines, situated in Calico desert. For many new players, first entering those caverns feels like hitting a wall: It's noticeably harder then the normal mines with its monsters doing much more damage, and without an elevator you always have to start from the very top.

There are many skull cavern guides already; however, most of them focus on deep diving, reaching level 100 or even end-game farming in the skull caverns. While useful and important, those guides don't really help beginners who have just unlocked the skull cavern and struggle to even make it through the first levels.

This is where this guide comes in; it should help you survive in the skull caverns on your first trips, slowly get geared up and more experienced, and lead you to the point where you can start trying for level 100 or deep farming runs. I will include some pointers for later game, but mark anything requiring ginger island or mastery as spoilers; beginners probably don't have access to those things anyway.

Minimum Requirements

Before you go into the skull cavern for the first time, there are some minimum requirements:

• You need to have unlocked the skull cavern, of course. Get to the bottom of the mine, and fix the bus, and you are good to go. Note that in 1.6 you can enter the skull cavern without reaching the bottom of the mines (you still need to unlock the bus) during desert festival in spring.
• Have at least a gold pickaxe. You want to upgrade it to iridium as soon as possible, but you probably won't have enough of it on your first trips to the skull cavern.
• You need a good weapon, at least a Lava Katana or Steel Falchion. The lava katana is the best weapon you can buy at the Adventurers guild before getting the Galaxy Sword, but its pretty expensive if you reach the skull cavern pretty early in the game. The Steel Falchion is weaker (does about the same damage as the Obsidian that you find on level 90), but is much faster - and this will help you fend off the pesky serpents in skull cavern.
  • If you got lucky and have found a prismatic shard, use it to get the Galaxy Sword before anything else. This will be your best weapon for a very long time! If you haven't got a prismatic shard yet, than this will actually be one of your main goals in the skull cavern.
  • Don't try to go in there with just the Obsidian Edge or even worse unless you know what your are doing. The weapon does make a huge difference. Similarly, don't use daggers. Clubs can be used if you have some experience with them, but for the beginning I really recommend a good sword.
• Not really a minimum requirement, but very very helpful is to have automated your farm as much as possible. The skull cavern rewards get better the deeper you go, and thus just going there in the late afternoon because your farm work takes so long won't really be worth it. A full day of cavern diving will get you much better bang for your buck than two half-days. Once you find auto-petters, those will also help your conscience for not petting your pets on skull cavern days. If you haven't automated your farm with sprinklers yet, you can still plan on using rainy days or the winter season for cavern runs.
• Finally: zoom out as much as possible. It really helps in skull cavern to see monsters, stone clusters or iridium nodes from as far away as possible.

Types of Skull Cavern Runs

Every time you go into the skull cavern, you should do so with a clear purpose or goal in mind. This purpose decides on how many resources you should invest into, and how exactly you should approach this run:

1. The first few times you go into the skull cavern, you should just try to get comfortable in there. You won't have good gear, nor the experience yet, so you probably won't get very deep. However, you can use those runs to get used to the monsters in skull cavern and how to survive them, can find your first iridium in order to upgrade your pickaxe and rings, and maybe even find your first prismatic shard for that Galaxy Sword.
   • In those runs, you really should use the time to learn and train: when do you have to swing at a serpent to knock it back without getting hit; how to best handle slimes by backing them against a corner and slashing away, how to deal with groups of monsters by retreating and or grouping them up. Improve your tactics, try to take less damage, try to get faster. During those types of runs, you should use the resources at your disposal (food buffs, bombs) in order to learn how to maximize their effects, but you probably won't have many of those resources anyway.
2. Once you get more comfortable in the skull caverns, and surviving in there feels easier, your runs will slowly shift towards farming runs. Here, the focus is less about learning, but more about getting resources and working towards a specific goal (e.g. getting 10 iridium for upgrading the pickaxe and crafting an iridium band, working on the monster slayer goals, or farming all the other useful goodies you get along the way, like food and bombs from monster drops and stone for staircases). Those runs will help you get geared up for the third type of run - the deep dive.
   • Many things can also be bought: Bombs at the dwarf, spicy eel and espresso at the desert trader, stone for staircases at robins; or directly exchange your jade for a staircase at the desert trader on sundays. The more money you invest, the less you need to be farming. If you do farming runs, always mindfully decide if the resources you invest are worth it: food buffs and staircases for invested floors nearly always are worth it, crafting bombs if you want to farm metal ores probably is not. Also note that some things, mostly iridium ore and treasure room items like autopetters, are much easier to farm with deep dives. Some people forgo those low-investment farming runs completely; however, espacially for beginners I think they are extremely helpful, because the more time you spend in skull cavern, the easier it gets once you finally do a deep dive.
3. Deep dives. This is when you go all in, use all your best resources and try to go as deep as possible in order to finally reach Mr. Qi on leven 100, or farm heaps of iridium and prismatic shards and auto-petters. This is also where you really want to check that the external conditions are all in your favor (e.g. daily luck, later also the mastery blessings) because the investment is extremely high - but so are the potential rewards.

Skull Cavern Runs

On days you want to do a skull cavern run, check the TV first thing in the morning. Daily luck has a huge influence on any run; and for deep dives you really want to wait for a good luck day because you really want to maximize the outcome for the huge investment in those runs. For learning runs luck does not really play a big role, and a farming run might still be worth it even on not-so-good luck days (though you will probably do a bit less well than on good luck days), but knowing your daily luck bonus is still helpful.

Once you decide to commit to the run, if you haven't already, clean out your inventory and get all necessary equipment: Sword and pickaxe, all your food, bombs and staircases. You can also leave a chest in the cavern entrace and swap equipment there - that way, you won't forget anything. Try not to bring anything extra - you will need all your inventory slots for loot. Try to keep the important items in the same slots for all runs, so that you always know where they are and quickly access e.g. your food or sword in an emergency.

Try to get to the skull cavern as soon as possible. Catch the bus as soon as Pam gets there, or even better: use a desert totem to get there even earlier. You can buy desert totems at the desert trader for 3 omni geodes; you should get enough omni geodes that you should never run out of totems and need to use the bus at some point in your play-through. Especially on deep dives warp to the desert right after waking up (and checking the TV, or course).

Once in the desert, run to the skull cavern and pop your buffs (speed buffs possibly even before you run there form the warp point). Enter and repeat:

1. Once you enter a new floor, try to get a fast impression of the floor: Is it an infested floor or has a really bad layout? Are there any ladders or shafts nearby? Any large stone clusters? Where are monsters that could potentially become a problem? Make a quick plan on how you want to proceed.
2. If there is a free shaft or staircase already, take it.
3. If its a bad floor (e.g. an infested or spiral floor), you usually want to place and use a staircase of your own right away. Those floors otherwise take a pretty long time, and time is the one thing you really lack in skull cavern runs. Just skip to the next floor.
4. Otherwise, do the following, in order of priority:
   1. If there are big clusters of stones nearby, bomb them. This is your best chance to find staircases. Try to avoid monsters for now; only kill those you really need to (which should just be serpents for the most part).
   2. Kill groups of monsters, and big slimes. Any killed monster has a good chance to yield a staircase.
   3. Mine stones. This is your worst option; if there are no monster groups and stone clusters are nearby, it's often better to just pop a staircase than start mining single stone blocks, but its still an option.
5. Once you find a staircase or shaft, immediately take it. Prioritize shafts - they will drop you much faster. If you don't find a staircase in a reasonable amount of time, you always have the option to place a staircase - use it.
6. Try to have a plan on how you balance mining resources with diving deeper. In the beginning, getting out of your way to mine a single iridium node might be worth it, because they are rare and you don't have the option yet to get very deep. However, on later farming runs, skipping single nodes might be better, because the time your spent walking there and mining it could instead get you deeper into the cavern, where iridium nodes become a lot more common. On endgame deep dives you might decide to actually ignore any node (even clusters) before reaching a certain level and only start farming at that point.
   • In any case, you should have a plan (depending or your investment into the run and your experience) and try to stick with it. However, more often than not, prioritizing getting deeper instead of mining right now is the better option.

At every point during your run, you should watch your health bar - once it drops to less then half, heal up (using the buff-less healing food). In the beginning, you can do so even earlier, and try to stay close to full health. Your health can drop really fast if you get swarmed and panic.

Also keep tab on your buffs - top up whenever they run out.

In single-player, open the menu when it gets too hectic. This pauses the game; which gives you time to calm down, plan ahead, maybe switch you inventory slot in order to heal right after unpausing, and check on health and buffs. You can also craft additional bombs or stairs from your found resources, and organize your inventory when necessary.

Try to use as much of the time as possible. This means potentially staying up until 2am and passing out in the skull cavern. You will never lose items from passing out - only from letting your health drop to 0. Thus, you will only lose some gold (up to 1000), which really should not matter too much at this point in the game. If you don't want to pass out, consider also bringing a farm totem to warp back, which is much faster than taking the bus.

Gear

All that is left is to discuss the gear, and potential upgrades in order to optimally prepare for skull cavern runs.

We start with permanent gear:

Pickaxe and Weapon

A gold pickaxe and either the steel falchion or lava katana was already mentioned in the minimum requirements. Try to upgrade your pickaxe to iridium as soon as possible, and use your first prismatic shard to get a galaxy sword. This will be your best weapon for quite a while. After you unlock ginger island, you can upgrade further: Enchant your pickaxe with swift or powerful (I prefer swift), and your sword with 3 rubies and the vampiric or crusader enchantment. Late game, upgrade it to an infinity sword. Other endgame builds exist for the infinity gavel and iridium needle - look for guides if you are interested.

Rings

As for rings, the best (pre-skull cavern) options to start out with are a glowstone ring, and either a slime-charmer ring or a crabshell ring. Both can help you survive - the slime-charmer ring completely negates damage from slimes, while the crabshell ring reduces the damage from all monsters. It's your call which your find better: do have more trouble getting swarmed by serpents or can you hold those back successfully, but than get ambushed by a slime from behind?

Once you have enough iridium, upgrade your glowstone ring to an iridium band. It gives all of the same QoL enchantments, plus a damage boost, which always helps. When you get good enough at surviving, or later when you unlock ring combining at the vulcano forge on ginger island, you can switch to other rings that help you dive deeper or get more profits from your skull cavern runs. The most useful in my opinion are the burglar ring (simply doubles monster drops), the lucky ring (luck always helps!) and the napalm ring (which causes killed monsters to explode, which will destroy nearby stones and increase the chance to find staircases/shafts). My endgame load-out is usually one iridium band + lucky ring, and one napalm + burglar ring (or a second lucky ring), but there are lots of other viable options.

Boots

Until you unlock ginger island, space boots are your best option, and you won't find an upgrade in the skull cavern. On ginger island, you can get the cinderclown shoes as the best upgrade. An argument could be made for mermaid boots, but most consider the cinderclown shoes best-in-slot.

Trinkets

Trinkets are 1.6 endgame combat-mastery items. The ones that help the most in skull cavern in my opinion are the Fairy Box for ease of mind (and the Qi hungry challange!), either an ice rod or magic quiver for crowd control, or a parrot egg for making additional money (also you don't usually focus on killing monsters in the skull cavern). Your choice of which to run - they all have different pros and cons. I suggest trying them out and finding your personal favorite.

And now for consumable items:

Food

For food, you want to bring 3 different kinds: for healing, food buffs, and drink buffs. Healing food can be cow or goat cheese (which is easy to farm in large quantities and gold quality and heals a lot), salads (cheap to buy), or really anything else: even a big stack of salmon berries works, although needing to eat some many of them is a bit of hassle. As long as you have a lot of it, and it gives no buffs, you are good. And I mean absolutely no buffs, not even a pesky Fishing +1, because any food buff overrides the previous buff and you really don't want to lose your luck and speed buffs for a useless fishing buff in the middle of a run.

You also want a food that provides a useful buff: luck is the most important, followed by speed, and far of attack and defense. Some of the most useful buff foods are Spicy Eel (easy to acquire from serpents and the desert trader), Lucky Lunch (best luck buff after rock candy), Pumpkin Soup (easy recipe and really useful for beginners), possibly crab cakes (drop from crabs in the cavern) and of course the best buff food: rock candy (expensive, really want to use that one for endgame deep dives).

For drink buffs, there are basically only two options: triple-shot espresso for speed (you can buy coffee and the recipe in the saloon), and ginger ale once you've unlocked ginger island. Top up any buff as soon as it runs out.

Bombs

Just get as many as possible, of all types. Bombs are one of the most important item of any skull cavern run! For deep dives, you want to bring at least a hundred, maybe more; for normal farming runs you have to decide how many you want to invest. Note that you can craft more inside the skull cavern from all the drops once the ones you brought are all used up.

A notable mention goes to the master sling-shot with explosive ammo, which makes blowing up rock clusters even faster - you don't have to walk there, and the ammo explodes instantly. Especially for smaller clusters along the edge or in narrow passageways, the slingshot can be much faster and complements the use of bombs for larger clusters.

Staircases

Always bring at least a few staircases (or at least a stack of stone to craft into staircases if necessary): Bad floors can really bog you down if you don't have any. Once you get a Crystalarium, you can use it to duplicate Jade and trade it for staircases at the desert trader on Sundays. Late game, many players keep multiple Crystalariums running, and then staircase down to level 100 or deeper in order to start their runs there - which makes them that much more effective. If you cannot reach level 100 even with your best efforts after reading this guide, or simply hate skull cavern, this is also a way to still get down as deep as you want (however, Mr. Qi will take note if you use more than 10 stair during your run).

Other buffs

Finally, there are a few other buffs you can get. The statue of blessings from farming mastery has a chance to give you a +1 luck buff for the day. The statue of the dwarf king from mining mastery has a range of useful buffs, the best of which in my opinion is the increased chance to find ladders. Finally, if you plan to do a skull cavern run during the desert festival, you can get the chef to make you a meal with rare fruit and uncomfortably hot sauce for a +3 luck, +1 speed buff, which is separate from other food and drink buffs and stacks with both.

Thus, the best possible day to do a skull cavern deep dive would be a maximum luck day during the desert festival, where you get the luck buff from the statue of blessings, and the ladder buff (or maybe ore buff at this point?) from the statue of the dwarf king. Eat your meal from the chef, pop your rock candy, drink your ginger ale and don your two lucky rings, and enjoy your +12 luck stacked on top of your +0.125 daily luck while you go down a few hundred staircases until you reach a depth where basically all nodes are iridium nodes. Enjoy! You earned it.