The Eldritch Scoundrel is more functional as a 'wizards apprentice', or secondary caster filling a similar role to a bard than a fully-fledged rogue. However, their abilities are heavily class dependent, including rogue/ninja talents. The most important being Vanishing Trick, which requires being at least 12th level before you are able to upgrade the talent into Invisible Blade. In addition, sneak attack is meaningless without an ability to land hits. The only ability that would be valuable for an Eldritch Scoundrel from Arcane Trickster would be Impromptu Sneak Attack, but only that feature. A 3 level dip, however, can be quite disruptive, and Eldritch Scoundrel has a number of tools for getting sneak attack already.
Question 2:
No. You could take levels in Evangelist, but would lose a class level and caster level and level of spell-casting. Could be more useful than Arcane Trickster depending on your chosen god. This does not provide Sneak Attack in of itself.
Question 3:
Due to Debilitating Strike, it is quite advantageous to utilize Two-Weapon Fighting for a standard rogue due to increasing your accuracy via Bewildered. However, using a weapon in both hands prevents spellcasting, and therefore isn't effective for an Eldritch Scoundrel due to competing for 'hands of effort'. You could utilize armor spikes to circumvent this. It is worth being mindful about hand usage as any caster.
Piranha Strike is less useful than Power Attack, and the damage overall is weaker than simply utilizing a one-handed finesse weapon, such as the rapier, and relying on sneak attack. You cannot use the feat with touch attack spells. In addition, your BAB does not increase quickly enough for the feat's damage to increase to a more respectable level. Overall, not a feat worth taking until much later unless you are satisfied with utilizing daggers, two-weapon fighting and taking Deific Obediance (Pharasma). If so, Piranha Strike becomes quite useful.
Combat Casting is a very useful feat for any caster that will be in melee, as well as Deific Obediance (Nethys), which stacks with Combat Casting.
Dampen Presence ensures that your invisibility is never beaten. Otherwise, blindsight will severely weaken your effectiveness.
Question 4:
Casters normally only need boost their spellcasting stat if they are attempting to utilize spells that require saving throws. Since the Eldritch Scoundrel either A) uses attack spells such as Shocking Grasp that rely only on caster level, or B) effects that do not require saving throws, they are not pressed to have a high casting stat, only enough to cast their highest level spells. A 16 is more than functional.
Instead, use your spellcasting as tools to expand your utility and combat functionality, and focus on increasing your Dexterity, and therefore your accuracy/damage. Consider the Eldritch Scoundrel as a 'wizard's apprentice' or 'utility belt' character. They can functionally carry all the tools and tricks that a wizard is famous for utilizing and put them to better use than the wizard themself in some cases. Paired with another spellcaster, an Eldritch Scoundrel can be an incredible boon for adventuring effectiveness and help alleviate pressure from an arcane caster for providing necessary tools and spells for emergencies, such as Feather Fall, Passwall, Tiny Hut, Water Breathing and Gaseous Form. A well-prepared Eldritch Scoundrel can be impossible to pin down and impossible to impede, and can even utilize God Wizard tactics, such as casting pit spells, summoning monsters and creating walls. Anything that a wizard is capable of achieving, an Eldritch Scoundrel could theoretically replicate.
General Advice:
Consider the Eldritch Scoundrel as a completely different class to the Rogue. They are not obsessed with dealing damage as much as a Rogue might be, but neither are they incapable of doing, nor entirely beholden to doing nothing but damage like most martials. With a combination of Sense Vitals and [Empowered-Intensified] Shocking Grasp/Snowball, the Eldritch Scoundrel can deal a significant amount of damage while also delivering a severe debuff on top of this. Think of Sneak Attack as simply another tool in your arsenal, and start thinking more in terms of being a caster with combat capabilities in a pinch.
'In a pinch' describes the class philosophy quite well.
You are the character with everything when it is needed while fully capable of functioning in a variety of capacities.
With the full wizard/sorcerer list, you can utilize an incredible quantity of wands and scrolls. With your own spellcasting, you are able to allow the party wizard to prepare extra damage/control spells by preparing all the utility spells, or add even more of these spells yourself.
With Weapon Finesse+Dex-to-Damage/Shocking Grasp/Snowball+Sneak Attack+Debilitating Injury, you are able to deal respectable amounts of damage while also having tools available to you that allow an Eldritch Scoundrel to deliver these abilities more effectively than a standard rogue.
Your skills are some of the best out of all classes, and Rogue's Edge provide incredible benefits to some of the most powerful skills, including Heal, Stealth, Perception and Disable Device. You are also still able to disable magical traps.
There are few things you cannot do. Rogue, with some prep, is still one of them. Wizard, with prep and resources, is another.
To calculate when a creature has been noticed or is being observed, consider that a Stealth attempt has allowed a creature to slip away into hiding, but the check itself is their ability to remain unobserved. How a creature can then perceive that hiding creature depends on their circumstances.
If the creature using Stealth attacked from hiding during a surprise round, then this must be resolved as its own Perception check to prevent being surprised, but not necessarily to observe the creature attacking. A creature prevented from being surprised and to observe their attacker are two separate checks, made at the same time as the creature breaks Stealth (with an attack, opposed by the creature's Stealth check to remain hidden upon an approach, to determine surprise) and then re-enters Stealth (the creature sniped/attacked in melee, then is able to re-enter Stealth either as a move action [Sniping] or as part of movement [Any attack other than ranged attacks], to determine a successful attempt at hiding).
If a creature makes their Stealth check as part of re-entering stealth, they were not observed at any point by the perceiving creature until the the attack, even if they were not surprised. Even a surprised creature can attempt to perceive their attacker as they enter stealth, but this does not prevent the creature from being surprised.
To find a creature currently in Stealth that you failed to observe as they entered Stealth, you must use a move action to locate the creature. If your Perception check beats the creature's Stealth check, then you know the location of the creature, and can perceive them unless some other effect prevents you from observing them (like invisibility).
You can passively make Perception checks, but you are never aware that you are making these checks at any point. This is to simulate your brain's natural ability to block out and give importance to particular stimuli, and your Perception being a more fine-tuned capability of determining when something is or is not important stimuli.
When you successfully perceive or know the location of a creature in Stealth, this does not mean other creatures can perceive the creature as well. Successfully determining a hidden creature's location does not also confer this to other creatures. They must make their own actions or Perception attempts to perceive the hidden creature. However, informing other creatures of a hidden creature's position entitles them to a reactive Perception check to locate the hidden creature and possibly allow them to perceive the hidden creature or determine its location.
Determining a creature's ability to perceive a hidden creature depends on functional stimulus. To be allowed to Stealth, a creature must have cover or concealment of any kind. Total concealment or total cover functionally prevent a creature from being observed visually, as they prevent a creature from having line of sight or line of effect respectively. Treat this as being invisible to an observer unable to perceive them through other senses.
If a creature is not moving, hidden within darkness, while a human without light to shine into the darkness is trying to perceive them, then the hidden creature is effectively invisible. In this situation, the human must beat a Perception DC of 20+the creature's Stealth score to be able to determine their location. This assumes the human knows that there is a hidden creature within the darkness. Otherwise, the human is not entitled to a reactive Perception check, as the creature is making no noise from moving, and is not perceivable by the human's senses.
If a creature is invisible (as the spell invisibility), then it is granted this benefit at all times on visual based Perception checks. An invisible creature cannot be perceived visually by any creature unable to see invisible creatures, and so these creatures are never entitled to a reactive Perception check due to visual stimulus.
If, in either case, the creature moves, and that movement is not muffled (such as from the silence spell), then a creature is entitled to a Perception check of a DC set by the moving hidden creature's Stealth check. This allows a creature to determine the invisible creature's location, but not to perceive them. This is because sound is a separate stimuli to vision. And so long as a creature is capable of hearing, they are able to make audio-based Perception checks.
@Sheness The Hollow & AdviceDroid (whom I assume are the same person, based on your use of the same terminology):
Based on your enthusiasm for the subject matter and your command of the requisite knowledge / rules...I strongly suggest you write a guide on this very specific topic.
I would read it great interest. As would others. Hurry, before this thread is relegated to eventual obscurity.
This unit will present adequate data.
Continuing Advice.
Archetypes of the Dead:
There are a number of undead focused archetypes and classes available for play. The major three are Necromancer Arcane School wizard (with the new Undead Master archetype from Horror Adventures, which is the archetype of Sheness the Hollow), Cleric (Undead Lord is less necessary for Cleric than Wizard's Undead Master archetype), and Oracle (using the Bones mystery). Some secondary choices are the Juju mystery for Oracle and the aforementioned Gravewalker witch archetype combined with the Hex Channeler archetype. The Dirge Bard and Necromancy implement Occultist are our tertiary choices. I will largely discuss the major three, as they function most closely to traditional necromancers, while others are either slightly inferior or only partially fulfill what we want. An army of the dead.
Undead Masters are an effective 'cheat' to make necromancers work for wizards, but also bring a variety of tools to their trade that the Undead Lord is simply incapable of replicating. Such necromancers do not even need to choose necromancy as a school, allowing for the clearly more powerful option of divination if desired. However, Improved Channel allows us to more easily maintain control over intelligent undead while we have them. We gain a fourth bucket for use with the Undead Master (and in turn, the Undead Lord), which is the Companion Bucket. This bucket can only contain a single undead creature, whose HD must not exceed our (effective) cleric level. We can apply a single template to a skeleton, such as bloody or burning, but this halves the HD limit. Largely, this is a fairly insignificant creature with a template applied. This is a renewable corpse alongside the restore corpse spell, and thus bloody is unnecessary to protect our investment like other skeletons.However, unlike most wizards, investing in a staff arcane bond is a very smart choice, and the Companion Bucket can be something of a redundant space filler. Helpful for mounts and utility undead (such as Giant Bats), however.
As a wizard, the Undead Master has a vast quantity of power at their disposal. While possessing an army as readily as any cleric, we can also utilize command undead without using a staff, and can apply metamagic feats. Additionally, the undead master will never prepare any important undead-related spells, as they are able to cast the spells they gain early from this archetype spontaneously. This allows us to prepare largely utilitarian spells, while still having access to animate dead when we require more undead.
As we already have command undead, we need easy access to desecrate. There are two choices. Voidsticks are reusable sources of desecrate that are relatively inexpensive. An alternative is simply a constant desecrate magic item, should a DM refuse to allow voidsticks, for obvious reasons as stated below.
The next method is to create a staff of desecrate like we would create a staff of command undead. This is a simple and elegant option, though more expensive than voidsticks.
For a Cleric, we can use many of the options as above save for command undead. However, we have a great deal more flexibility with our archetypes, and we are not required to take the dedicated undead archetype. In fact, I highly recommend not doing so, and choosing one that allows you to be more capable outside of undead. Do not focus entirely on undead other than taking Command Undead and making the staff. You can, at that point, be anything you choose to be, much like a standard cleric can easily fill a variety of roles. Undead are, for you, simply another tool at your disposal.
A Bones Oracle must take revelations to gain their necromantic powers, and it takes longer for Bone Oracles to truly match the raw creature output of the other choices. However, as a Charisma-based spontaneous caster, their Command Undead revelation is far more powerful than either of the previous options and allows it to be used as an offensive tool rather than simply as an additional bucket for overflow. Additionally, they can summon an undead minion to fight for them of a HD equal to their oracle level. Prepare good choices for your HD that suit a variety of situations, and bring out an undead that works best for a given encounter. Once the Bone Oracle reaches 6th level, they gain animate dead, and are able to now keep pace with our other options. Much like the other options, look for ways to function outside the undead. Consider taking Warsighted to become more capable at martial combat, or consider buffing and summoning to add even more bodies onto the battlefield.
While leveling, you may think to consider the Agent of the Grave PrC. Then consider waiting for Favored Prestige Class and Prestigious Spell-casting feats to be released to the public before assessing that option. Once publicly available, this is then a potent option for wizard necromancers. While helpful for our other choices, the wizard gains access to desecrate as an extraordinary ability (unusual), and a few useful necromancy spells to our spell list if we need them, as well as some additional benefits, like an increased hit dice and Charisma to hit points rather than Constitution for every level beyond your first Agent of the Grave level. Any features we might lose are hardly missed and easily replaced within Agent of the Grave.
Voidstick Zombie: Available or Not?:
As of right now, there exist no means of determining the power of a voidstick zombie of a lower hit dice than the base creature. So consider asking your DM how this might function, as a voidstick zombie unleashed within a horde functions as constant healing for undead and a walking desecrate, and we can maintain control over it through command undead. As written, however, this produces a 15 HD monster with an unreasonable amount of power regardless of what HD the base creature might have been. Find a commoner. Create a killing machine. A DM should balance this to be far more reasonable. Discuss with them reasonable alternatives, such as simply reducing the creature's HD and channel power to match the base creature's HD, and removing feats except for Improved Channel and Toughness, which might be racial feats.
An important concept for undead management is to section your undead into 'buckets'. Each bucket has a different weight, and you should evaluate where you place your undead in these buckets. The three buckets any necromancer should possess are; Spell (Animate Dead), Feat (Command Undead feat) and Staff (Command Undead spell, using a staff).
We already know how the Animate Dead Spell Bucket can be added to, but not what happens when we want to rotate undead out of it to free space elsewhere. When your spell bucket overflows due to adding too much HD in undead, you must relinquish control over enough undead to dip back beneath or meet your maximum HD. This can be problematic for resource investment and personal safety. Therefore, we have our alternative buckets to handle overflow.
Necromancer wizards, clerics with Command Undead and Bone Oracles with the Command Undead revelation gain access to the Feat Bucket, using the Command Undead feat to control an amount of undead whose total HD are equal to your effective cleric level. This is significantly smaller than your Animate Dead Spell Bucket, but there is a reason. A) With this feat, you can steal control of undead you have not raised, making for excellent cannon fodder, and B) you can push excess undead from Animate Dead into your Feat Bucket. Mindless undead do not get to save after the initial save, but intelligent undead receive a save each day. Utilize intelligent undead while you have them.
Then, we have the Staff Bucket. The reason this is the Staff Bucket is due to command undead not being available to clerics or oracles normally. But, with a staff of command undead and cause fear (the amount of gold is undiscernable at this time as I lack access to my full records on this presently), a cleric and oracle can spells from the staff using their caster level and Wisdom modifier, and recharge the staff with cause fear . This presents a new bucket to exploit, as command undead is a save to resist only for intelligent undead, and lasts for a day per caster level, and has no HD restrictions. Shifting undead into this bucket is simple, but using this staff to gain access to stray powerful undead can be equally as beneficial. The fact that intelligent undead are forced to obey your commands makes this also the one sure method of maintaining control of intelligent undead. However, be mindful of your charges and ensure they are topped up frequently. You have been warned.
Animate Dead requires that you spend an amount of onyx gem with a value equal to the HD of all the undead you intend to raise within the area of your animate dead spell. The amount of dead you can raise with a single casting, or their total Hit Dice from the base creatures (excluding any class levels and class HD they may have possessed, which are lost once raised) is equal to twice your caster level. However, the total quantity of undead you can control with this spell is 4HD per caster level. This is an introduction to our biggest 'bucket', which I will explain later.
As an example, say we are a 5th level cleric with animate dead. Our caster level is 5, so our bucket size is 20HD and our maximum HD we can raise in a single casting is 10HD. We have an onyx equal to 250GP, which allows us to creature a zombie or skeleton of 10HD. We cannot use multiple onyx pieces for this process, even if their value equals 250gp.
We have 10 human corpses and a chuul corpse. The 250gp gem is able to create either 10 human skeletons, 9 human zombies, or a chuul skeleton. The reason we cannot create more zombies is due to zombies gaining additional hit dice based on size. This needs to be factored into creating undead.
If we wanted to apply a template to these undead, we would need to be able to raise one of these corpses for an additional amount of HD for every template we want to apply, and use an appropriate onyx for the result. This does not affect the amount of HD of undead we can control. This is only important for A) how many undead we can raise with a single casting of animate dead and B) how expensive the onyx gem must be.
In our previous example, we cannot raise a chuul skeleton with a template, as it would exceed our maximum limit (we would need to be CL 10 to apply one template, and CL 15 to apply two). But, we can raise 3 of our human corpses using the 250gp onyx into bloody burning human skeletons. We could also raise one into a fast brain-eating zombie, and an additional 2 human zombies with the same spell, using up the onyx.
If we use a desecrate spell in this area, we can double the amount of undead we can create, allowing for easier access to templates, and with a more expensive onyx gem (750gp), we could have raised the chuul corpse into a bloody burning chuul skeleton. We also then grant all undead raised a +1 hit point per HD permanently. This is even better by a shrine, doubling the bonus. Undead are also empowered in an area of desecrate, so there are offensive benefits to the spell.
I will eventually explain buckets, archetypes and useful things about necromancy. For now I must power down.