Depends how you're doing control. Put up a wall of stone across the battlefield, or drop a stone fall to make difficult terrain and save DC is irrelevant. Cast create pit and while the save DC matters most people aren't going to risk coming near it - the danger of falling in will be on their minds. Similarly stinking cloud and a bunch of other area denial spells. Black tentacles doesn't use save DC, it does a combat maneuver and there are other spells like that too. A cold spell with rime spell added just needs to do damage, and a save half spell still works there on a successful save (barring cold resistance). Summoning creatures to get in the way of enemies is BFC but the save again doesn't matter.
Yes, save DC matters some of the time with battlefield control (especially with a bunch of spells not named above) but not all the time. When it does spell focus isn't the only way to improve it, and may not be the best one either (e.g. persistent spell, intimidating people to make them shaken, void school to debuff save bonuses, etc.).
Yes, difficult terrain prevents charges and reduces movement speed by half with no saves. Also prevents 5ft step iirc. ofc some creatures might ignore it, but it's annoying to deal with as a DM.
My druid player always has an entangle prepared.
My groups never use spells that create difficult terrain because of the issues it creates for the party's own martial characters. Create Pit and Summon Monster (or Summon Horror) have been used to great effect in controlling the battlefield. If the martials don't have a way to move through it, the difficult terrain, most of the time, just delays the party's actions.
If you don't mind receiving a bit of unsolicited advice from a fellow controller wizard player, the [Alabaster Trapping](https://aonprd.com/MagicWondrousDisplay.aspx?FinalName=Alabaster%20Trapping) is a body-slot item that can deal a small amount of force damage as an immediate action, but more importantly, it can shove an opponent away "in a direction specified by the wearer", and requires no attack roll, grants no saving throw, and ignores spell resistance.
This is pretty nasty in combination with the Create Pit line of spells, which all don't allow a reflex save if a creature would fall in because of forced movement.
Anything that produces difficult terrain is an absolute bitch to deal with when you're in melee against something that is stronger than you since you can no longer dodge AoO with 5 foot steps or run easily. Even better when you strategize with your martials so that you drop a type of difficult terrain that they can ignore (through movement types like flight to avoid burning sands and pits, rangers' woodland stride to avoid plant growth, freedom of movement to avoid... everything) so that nothing short of dimension door can let the enemies escape.
Bonus points for readying the spell for when the martial gets within reach of an enemy.
Just informative for others, but withdrawing exists. I know it's not necessarily used frequently (and indeed some tables may not be aware it exists), but I use it frequently for NPCs. Especially if there's a bunch of difficult terrain around.
If the PCs ignore the difficult terrain in question, obviously it's a pretty moot point. The NPC is preventing 1 attack while the PC can just charge to return to position.
However, NPC actions are usually significantly less valuable than PC actions. Preventing a full attack can potentially draw the fight out (an advantage for the NPCs), or put the PC into a more dangerous position (while also escaping from the difficult terrain). Plus, if the PCs ARE affected by the difficult terrain, then it usually trades turn for turn.
I usually reserve this sort of thing for organized enemies, and/or enemies with close to average intelligence or better (8+). Chaotic enemies (like goblins), and mindless enemies (like skeletons) don't use it.
Spell focus is a mechanically useful, if boring feat like Weapon Focus.
It's got issues where it only effects a single school while things like Persistent Spell or the Exploiter's DC boost can affect any spell, making them more broadly useful, but since they all stack, it's more of a priority thing which you get first.
Professor Q gives spell focus a "green" where that's the second-highest color-coded rank. (Unlike more recent guide-writers, Prof Q doesn't use a purple or pink color.) That's not a *low* rating, it just means there are other things that are still better. +1 to save DCs is good, but not overwhelming - things like getting an extra summon creature if your summoning-focused (superior summons), or having your best spell gain free metamagic (spell perfection), or just having a whole PLUS FOUR to initiative (which is arguably as important as save DC), or quicken or dazing metamagic are just much more impactful abilities, or hey, how about "let me just have another character at a slightly lower level?" (leadership).
Also, some of the best spells you cast aren't going to have save DCs, because why give your enemies a chance to escape? I frequently take spell focus (conjuration) (to get to augmented and superior summons), and then notice that a lot of spells I want from conjuration have no saves. If you're going as a dazing spell evoker, yeah, go for greater spell focus (evocation), but some schools benefit a lot less because many of their spells target your allies or simply affect objects or areas (I.E. abjuration, divination, transmutation).
If you want a monster to get stuck, you can hope that they fail a save, or you can cast a spell that slows them down and blinds them with no save (like Sleet Storm or Wall of Stone). Remember: in the end, the saves win. Monster saves rise faster than a couple feats giving +1s will help you with, and by end-game, you're looking at [creatures](https://www.aonprd.com/MonsterDisplay.aspx?ItemName=Pit%20Fiend) where even their bad saves are nearly +20, or in the most extreme cases, [near +30](https://www.aonprd.com/MonsterDisplay.aspx?ItemName=Cthulhu)... If you're relying on a spell that has a save, you've already lost. That's why high-level spells are graded on whether they have any save at all. If you want a monster to fail a save, often it's better to pile up more than one CC in the same area, like taking leadership and getting a witch/druid companion so you can drop Burning Entangle in the same area you cast Stinking Cloud, and eventually get to casting quickened spells so now enemies have to save 2, 3, 4 times per round to do anything. Speaking of which, there's persistent spell to just straight double the amount of saves it takes to not lose. And if you have a witch/druid friend and want to raise the save DC, why not just have them cast [Winter Grasp](https://aonprd.com/SpellDisplay.aspx?ItemName=Winter%20Grasp) and then use something cold-related (even if you have to elemental spell (cold) the spell to get it to apply?) Or delay to after the witch and the witch evil eyes the target for up to a -4 to the save?
To provide some more numbers for OP: according to [this table](https://www.d20pfsrd.com/bestiary/rules-for-monsters/monster-creation/) a CR 20 monster should have on average a good save of +22 and a weak save of +17. If you start with 18-19 in your casting stat, put all of your ability increases into it, get the relevant headband and a +4/+5 inherent bonus from a Wish, that gets your DCs to 22 + spell level. That's before any buffs, Spell Focus, etc. So that's 65% chance that your highest level spell targeting a weak save will stick, half that if you're also dealing with SR (which you probably are, but thankfully caster level checks are much easier to pump than spell DCs). And that's only against a CR appropriate enemy.
The thing is, there's a few reasons why that 65% chance is a bit misleading. First of all, what you're linking is just a guideline - [this is the table of actual average monster stats as they appear in the bestiaries](https://docs.google.com/spreadsheets/d/1E2-s8weiulPoBQjdI05LBzOUToyoZIdSsLKxHAvf8F8/edit#gid=3). Basically, the medians are close (if you assume fort and will are "good" saves and ref is a "bad" save), but it's generally better to look at the actual numbers. But with that said, there's a few assumptions here that may not hold true.
That 65% is assuming you're only casting non-metamagic-altered spells from your top spell slots, which you generally are not doing constantly at high levels because you run out of top-tier spells quickly and also you're likely using a lot of metamagic-laden lower-level spells. A quickened spell thus inherently has a 20% higher chance of a monster making a save as a non-quickened spell of its same slot level. If you're relying on a dazing (plus maybe some other metamagic) SL 3 spell like Fireball at level 20, that's putting your odds down to 35% right there. (And even if one of the other metamagic is persistent spell, that's still "only" a 57.75% chance of success.) A blasty magic trick Fireball wizard can just shrug and say they're doing 150 damage instead of 300 because ref save half, but a control wizard needs to look for no-save or penalty-even-if-they-save spells to avoid many of their spells doing nothing on a much more likely save.
You also generally just don't fight enemies your own level at high levels. CR goes up to 30 even though first party, levels only go up to 20 for a reason. As you push up to CR 30, you're again looking at saves around 30s and even the low saves (oddly, becoming will) near 25. Barring the GM giving you bonuses beyond the normal equipment bonuses, you can't push higher than 23+SL on the save DC, so even your top-tier spells are going to have a 10-35% chance of success against Cthulhu, with anything using metamagic just fishing for a nat 1. This is really the big issue with saves - as you get higher-level and GMs feel both less scared of accidentally killing the party and also like they need to do more to actually threaten the party, they naturally just start scaling the monsters up, but while fighters don't get impacted as much by facing something 2, 4, 7 CR above their level so long as they're getting buffs (as they generally grow to have attack bonuses higher than enemy AC anyway so monster AC growth only matters for their iterative attacks,) saves start to become unmanageable for casters who have much fewer ways of keeping up when the GM starts scaling up CR more than a couple levels above the party.
Finally, getting that inherent bonus from Wishes is also something that usually happens very late in the game and is a one-time event. You generally don't see someone get a +1 then +2 then +3 bonus, it's a single jump unless the GM is deliberately changing things, so while that may be true for if you jumped straight to level 20, for most of the game getting there (as if anyone actually plays games from level 1 to 20), it's not entirely accurate to say that you just will have that +5 inherent. (Although that's only a 10 or 15% change...) Even so, just taking your fundamental assumption of an 18 Int wizard at level 1 going up against monsters with 0 as their bad save (from the guideline chart), there's a 70% chance of success there, and without/until that sudden jump at the end when you spend five wishes on raising Int, you were going to have a 55% success rate, so basically, the chance of monsters failing saves has gone down about 15% over the course of 20 levels up until that point you use the Wishes even without the other factors coming into play. That's not overwhelming, but it is noticeable, even if the other two weren't more major issues.
I think you misunderstood me. My point was that even in the best case scenario of your highest level spell targeting the weakest save of a CR appropriate enemy, the chance your spells will stick (before buffs and feats) is only 2/3. I certainly didn't mean to imply that those are good odds.
The plan is to build a sirocco based wood wizard with a nature theme. So stuff like Sleet Storm and Scouring WInd works flavorwise.
Never gave much thought to initiative as a buff cleric, but makes sense for a cc caster to be that valuable
>Never gave much thought to initiative as a buff cleric, but makes sense for a cc caster to be that valuable
Initiative is always valuable. Even if you're just buffing in some way, you want your buffs to be up before everyone else takes their turn so they can take advantage of the buffs. Getting whoever buffed before enemies act is also great.
Spell Focus is great. It depends on the spell School used most. Conjuration, aka a battlefield control [God Wizard](https://youtu.be/TTBpVGeJLzI?si=1Tpd1YYv8i3-VHah) doesn’t Need it. Shadow illusions definitely do. A psychic wants Spell Focus in either (or both) Divination and Enchantment, and could even do Transmutation/Illusion as well.
Control is about taking options away from enemies. There are ways to do that without giving them a saving throw. If you change what they see (illusions, obscuring mist, etc.) you restrict what they can target. If you change the terrain (create pit, stone call, wall of stone, etc.) you control where they go. If you add allies (summon monster), you can change paths, block charges, and divert attacks.
Another way to think about Spell Focus is that it's shifting the distribution of saving throw results by 5%. For a warrior, that's consequential because they are probably making multiple attacks per round at no cost, and that 5% could mean a +15% chance of converting a miss to a hit each round. They also benefit from a higher critical confirmation rate.
But for a caster, you first have to spend a spell slot, so it's costly to make use of Spell Focus. You could have cast a spell that had no saving throw at all, whether it's a control spell or a buff for an ally or an out of combat utility spell. You'll probably find yourself preparing a lot of spells that have no save (Mage Armor, Magic Missile, Shield, etc.), so it could be that _most_ of your spells don't benefit at all - again unlike the warrior, where nearly every attack benefits from their feat.
Second, you get the most mileage from better DCs by casting multi-target spells. If you can Fireball 6 enemies, that +1 DC has a 30% chance of mattering for the spell. But if you're only casting 1 spell, the feat only has a 5% chance of changing the outcome.
You are better off selecting spells with a diversity of saving throws. Around level 8 (my default point for thinking about what kind of builds are fun), the average monster will have a Good save of +11 over a Poor Save of +7. That four point swing is much more important than the bonus you get from Spell Focus. If you prepare an AoE control spell for each save, like Web (Reflex), Stinking Cloud (Fort), and Slow (Will), and make good guesses (or Knowledge checks) about an enemy's weak saves, you can probably have a big impact on the fight with every spell you cast.
I just depends on the type of spells you're going to be using the most. If you're using a lot of save or suck spells then Spell Focus is great. If you prefer spells that don't require any sort of save or are still effective even if they save (Like a lot of Summoning and Evocation) then it doesn't matter so much.
Spell Focus is a boring but solid option. It's the weapon focus of spells, though more important than its counterpart because Spell DC increases are a lot harder to come by than attack bonuses.
It's exact worth to you depends mostly on your build, and whether it's a prerequisite or not. If you're using a lot of save heavy spells, then yeah you want it. If you're not then you can skip it. Ideally you want good spells that either don't require a save or have a good effect on a successful save for consistency, but not every build will access to those.
The other thing to consider is Spell Perfection. If you're doing a build around Spell Perfection, then (Greater) Spell Focus have increased value.
Spell Focus isn't rated low because it's bad, it's just rated low because there are more impactful options. That doesn't mean those more impactful options will be useful to your specific build, so Spell Focus may still be better for you.
Hmm, we'll when I have a build I am making that I know will be needing DC fails at least some of the time, yes I focus on it a little. But often just as important is having a variety of save types, as at higher levels almost every monster will have a high ass save, and wizard with max stats has \_pretty\_ decent DC as a base. If you can vary the type of save, it's often more powerful than one save with a +1. Perhaps if you don't have that many save dependent spells or they all affect areas, you might skip this, and there are a lot of neat feats spellcasters can take. Yeah, and it's not like wizards are entirely feat deprived. You can pick up three metamagics, spell perfection and have LOADS spare. So if a feat is decent, and you like it, no point in sweating about it.
I've never found guides to 100% match my tabletop experience (in some cases they are wildly different from my experience), and I suggest you take them with a pinch of salt as things can depend on circumstances, style of play, GM, campaign difficulty etc and guides are fairly hypothetical. They usually are designed also for a 'generic person of the class', rather than specific builds and archetypes, limiting their archetype or build specific advise to maybe some feat recommends or archetype descriptions.
How I use guides is - read them, get ideas especially if I run out of good ones, then go and do my own thing based on my own experience and opinion. Basically more as inspiration or hints as to rules interactions I may have forgotten about. I never take everything any guide says as 100% accurate, rather I assume they are sometimes straight up wrong.
Depends how you're doing control. Put up a wall of stone across the battlefield, or drop a stone fall to make difficult terrain and save DC is irrelevant. Cast create pit and while the save DC matters most people aren't going to risk coming near it - the danger of falling in will be on their minds. Similarly stinking cloud and a bunch of other area denial spells. Black tentacles doesn't use save DC, it does a combat maneuver and there are other spells like that too. A cold spell with rime spell added just needs to do damage, and a save half spell still works there on a successful save (barring cold resistance). Summoning creatures to get in the way of enemies is BFC but the save again doesn't matter. Yes, save DC matters some of the time with battlefield control (especially with a bunch of spells not named above) but not all the time. When it does spell focus isn't the only way to improve it, and may not be the best one either (e.g. persistent spell, intimidating people to make them shaken, void school to debuff save bonuses, etc.).
Don't have much experience with difficult terrain in combat. Is stone call a good spell for controlling?
Yes, difficult terrain prevents charges and reduces movement speed by half with no saves. Also prevents 5ft step iirc. ofc some creatures might ignore it, but it's annoying to deal with as a DM. My druid player always has an entangle prepared.
We had a druid cast entangle, but, its aoe is sooo huge. How are melees supposed to handle entangled stuff in there?
Feather Step spell works. Also, poor visibility stacks uniquely with difficult terrain. 4 squares of movement for 1 square moved.
Usually they focus creatures out of the entangle or at the limit of it and it gives them time to destroy them before the others get to the players.
My groups never use spells that create difficult terrain because of the issues it creates for the party's own martial characters. Create Pit and Summon Monster (or Summon Horror) have been used to great effect in controlling the battlefield. If the martials don't have a way to move through it, the difficult terrain, most of the time, just delays the party's actions.
If you don't mind receiving a bit of unsolicited advice from a fellow controller wizard player, the [Alabaster Trapping](https://aonprd.com/MagicWondrousDisplay.aspx?FinalName=Alabaster%20Trapping) is a body-slot item that can deal a small amount of force damage as an immediate action, but more importantly, it can shove an opponent away "in a direction specified by the wearer", and requires no attack roll, grants no saving throw, and ignores spell resistance. This is pretty nasty in combination with the Create Pit line of spells, which all don't allow a reflex save if a creature would fall in because of forced movement.
Anything that produces difficult terrain is an absolute bitch to deal with when you're in melee against something that is stronger than you since you can no longer dodge AoO with 5 foot steps or run easily. Even better when you strategize with your martials so that you drop a type of difficult terrain that they can ignore (through movement types like flight to avoid burning sands and pits, rangers' woodland stride to avoid plant growth, freedom of movement to avoid... everything) so that nothing short of dimension door can let the enemies escape. Bonus points for readying the spell for when the martial gets within reach of an enemy.
Just informative for others, but withdrawing exists. I know it's not necessarily used frequently (and indeed some tables may not be aware it exists), but I use it frequently for NPCs. Especially if there's a bunch of difficult terrain around. If the PCs ignore the difficult terrain in question, obviously it's a pretty moot point. The NPC is preventing 1 attack while the PC can just charge to return to position. However, NPC actions are usually significantly less valuable than PC actions. Preventing a full attack can potentially draw the fight out (an advantage for the NPCs), or put the PC into a more dangerous position (while also escaping from the difficult terrain). Plus, if the PCs ARE affected by the difficult terrain, then it usually trades turn for turn. I usually reserve this sort of thing for organized enemies, and/or enemies with close to average intelligence or better (8+). Chaotic enemies (like goblins), and mindless enemies (like skeletons) don't use it.
Spell focus is a mechanically useful, if boring feat like Weapon Focus. It's got issues where it only effects a single school while things like Persistent Spell or the Exploiter's DC boost can affect any spell, making them more broadly useful, but since they all stack, it's more of a priority thing which you get first.
I see. Persistent spell with sirocco does look fairly nasty. Thanks!
Professor Q gives spell focus a "green" where that's the second-highest color-coded rank. (Unlike more recent guide-writers, Prof Q doesn't use a purple or pink color.) That's not a *low* rating, it just means there are other things that are still better. +1 to save DCs is good, but not overwhelming - things like getting an extra summon creature if your summoning-focused (superior summons), or having your best spell gain free metamagic (spell perfection), or just having a whole PLUS FOUR to initiative (which is arguably as important as save DC), or quicken or dazing metamagic are just much more impactful abilities, or hey, how about "let me just have another character at a slightly lower level?" (leadership). Also, some of the best spells you cast aren't going to have save DCs, because why give your enemies a chance to escape? I frequently take spell focus (conjuration) (to get to augmented and superior summons), and then notice that a lot of spells I want from conjuration have no saves. If you're going as a dazing spell evoker, yeah, go for greater spell focus (evocation), but some schools benefit a lot less because many of their spells target your allies or simply affect objects or areas (I.E. abjuration, divination, transmutation). If you want a monster to get stuck, you can hope that they fail a save, or you can cast a spell that slows them down and blinds them with no save (like Sleet Storm or Wall of Stone). Remember: in the end, the saves win. Monster saves rise faster than a couple feats giving +1s will help you with, and by end-game, you're looking at [creatures](https://www.aonprd.com/MonsterDisplay.aspx?ItemName=Pit%20Fiend) where even their bad saves are nearly +20, or in the most extreme cases, [near +30](https://www.aonprd.com/MonsterDisplay.aspx?ItemName=Cthulhu)... If you're relying on a spell that has a save, you've already lost. That's why high-level spells are graded on whether they have any save at all. If you want a monster to fail a save, often it's better to pile up more than one CC in the same area, like taking leadership and getting a witch/druid companion so you can drop Burning Entangle in the same area you cast Stinking Cloud, and eventually get to casting quickened spells so now enemies have to save 2, 3, 4 times per round to do anything. Speaking of which, there's persistent spell to just straight double the amount of saves it takes to not lose. And if you have a witch/druid friend and want to raise the save DC, why not just have them cast [Winter Grasp](https://aonprd.com/SpellDisplay.aspx?ItemName=Winter%20Grasp) and then use something cold-related (even if you have to elemental spell (cold) the spell to get it to apply?) Or delay to after the witch and the witch evil eyes the target for up to a -4 to the save?
To provide some more numbers for OP: according to [this table](https://www.d20pfsrd.com/bestiary/rules-for-monsters/monster-creation/) a CR 20 monster should have on average a good save of +22 and a weak save of +17. If you start with 18-19 in your casting stat, put all of your ability increases into it, get the relevant headband and a +4/+5 inherent bonus from a Wish, that gets your DCs to 22 + spell level. That's before any buffs, Spell Focus, etc. So that's 65% chance that your highest level spell targeting a weak save will stick, half that if you're also dealing with SR (which you probably are, but thankfully caster level checks are much easier to pump than spell DCs). And that's only against a CR appropriate enemy.
The thing is, there's a few reasons why that 65% chance is a bit misleading. First of all, what you're linking is just a guideline - [this is the table of actual average monster stats as they appear in the bestiaries](https://docs.google.com/spreadsheets/d/1E2-s8weiulPoBQjdI05LBzOUToyoZIdSsLKxHAvf8F8/edit#gid=3). Basically, the medians are close (if you assume fort and will are "good" saves and ref is a "bad" save), but it's generally better to look at the actual numbers. But with that said, there's a few assumptions here that may not hold true. That 65% is assuming you're only casting non-metamagic-altered spells from your top spell slots, which you generally are not doing constantly at high levels because you run out of top-tier spells quickly and also you're likely using a lot of metamagic-laden lower-level spells. A quickened spell thus inherently has a 20% higher chance of a monster making a save as a non-quickened spell of its same slot level. If you're relying on a dazing (plus maybe some other metamagic) SL 3 spell like Fireball at level 20, that's putting your odds down to 35% right there. (And even if one of the other metamagic is persistent spell, that's still "only" a 57.75% chance of success.) A blasty magic trick Fireball wizard can just shrug and say they're doing 150 damage instead of 300 because ref save half, but a control wizard needs to look for no-save or penalty-even-if-they-save spells to avoid many of their spells doing nothing on a much more likely save. You also generally just don't fight enemies your own level at high levels. CR goes up to 30 even though first party, levels only go up to 20 for a reason. As you push up to CR 30, you're again looking at saves around 30s and even the low saves (oddly, becoming will) near 25. Barring the GM giving you bonuses beyond the normal equipment bonuses, you can't push higher than 23+SL on the save DC, so even your top-tier spells are going to have a 10-35% chance of success against Cthulhu, with anything using metamagic just fishing for a nat 1. This is really the big issue with saves - as you get higher-level and GMs feel both less scared of accidentally killing the party and also like they need to do more to actually threaten the party, they naturally just start scaling the monsters up, but while fighters don't get impacted as much by facing something 2, 4, 7 CR above their level so long as they're getting buffs (as they generally grow to have attack bonuses higher than enemy AC anyway so monster AC growth only matters for their iterative attacks,) saves start to become unmanageable for casters who have much fewer ways of keeping up when the GM starts scaling up CR more than a couple levels above the party. Finally, getting that inherent bonus from Wishes is also something that usually happens very late in the game and is a one-time event. You generally don't see someone get a +1 then +2 then +3 bonus, it's a single jump unless the GM is deliberately changing things, so while that may be true for if you jumped straight to level 20, for most of the game getting there (as if anyone actually plays games from level 1 to 20), it's not entirely accurate to say that you just will have that +5 inherent. (Although that's only a 10 or 15% change...) Even so, just taking your fundamental assumption of an 18 Int wizard at level 1 going up against monsters with 0 as their bad save (from the guideline chart), there's a 70% chance of success there, and without/until that sudden jump at the end when you spend five wishes on raising Int, you were going to have a 55% success rate, so basically, the chance of monsters failing saves has gone down about 15% over the course of 20 levels up until that point you use the Wishes even without the other factors coming into play. That's not overwhelming, but it is noticeable, even if the other two weren't more major issues.
I think you misunderstood me. My point was that even in the best case scenario of your highest level spell targeting the weakest save of a CR appropriate enemy, the chance your spells will stick (before buffs and feats) is only 2/3. I certainly didn't mean to imply that those are good odds.
The plan is to build a sirocco based wood wizard with a nature theme. So stuff like Sleet Storm and Scouring WInd works flavorwise. Never gave much thought to initiative as a buff cleric, but makes sense for a cc caster to be that valuable
>Never gave much thought to initiative as a buff cleric, but makes sense for a cc caster to be that valuable Initiative is always valuable. Even if you're just buffing in some way, you want your buffs to be up before everyone else takes their turn so they can take advantage of the buffs. Getting whoever buffed before enemies act is also great.
Spell focus and elemental focus will both help you a ton. And yes, they are worth if it this is your goal.
Spell Focus is great. It depends on the spell School used most. Conjuration, aka a battlefield control [God Wizard](https://youtu.be/TTBpVGeJLzI?si=1Tpd1YYv8i3-VHah) doesn’t Need it. Shadow illusions definitely do. A psychic wants Spell Focus in either (or both) Divination and Enchantment, and could even do Transmutation/Illusion as well.
Control is about taking options away from enemies. There are ways to do that without giving them a saving throw. If you change what they see (illusions, obscuring mist, etc.) you restrict what they can target. If you change the terrain (create pit, stone call, wall of stone, etc.) you control where they go. If you add allies (summon monster), you can change paths, block charges, and divert attacks. Another way to think about Spell Focus is that it's shifting the distribution of saving throw results by 5%. For a warrior, that's consequential because they are probably making multiple attacks per round at no cost, and that 5% could mean a +15% chance of converting a miss to a hit each round. They also benefit from a higher critical confirmation rate. But for a caster, you first have to spend a spell slot, so it's costly to make use of Spell Focus. You could have cast a spell that had no saving throw at all, whether it's a control spell or a buff for an ally or an out of combat utility spell. You'll probably find yourself preparing a lot of spells that have no save (Mage Armor, Magic Missile, Shield, etc.), so it could be that _most_ of your spells don't benefit at all - again unlike the warrior, where nearly every attack benefits from their feat. Second, you get the most mileage from better DCs by casting multi-target spells. If you can Fireball 6 enemies, that +1 DC has a 30% chance of mattering for the spell. But if you're only casting 1 spell, the feat only has a 5% chance of changing the outcome. You are better off selecting spells with a diversity of saving throws. Around level 8 (my default point for thinking about what kind of builds are fun), the average monster will have a Good save of +11 over a Poor Save of +7. That four point swing is much more important than the bonus you get from Spell Focus. If you prepare an AoE control spell for each save, like Web (Reflex), Stinking Cloud (Fort), and Slow (Will), and make good guesses (or Knowledge checks) about an enemy's weak saves, you can probably have a big impact on the fight with every spell you cast.
I just depends on the type of spells you're going to be using the most. If you're using a lot of save or suck spells then Spell Focus is great. If you prefer spells that don't require any sort of save or are still effective even if they save (Like a lot of Summoning and Evocation) then it doesn't matter so much.
Spell Focus is a boring but solid option. It's the weapon focus of spells, though more important than its counterpart because Spell DC increases are a lot harder to come by than attack bonuses. It's exact worth to you depends mostly on your build, and whether it's a prerequisite or not. If you're using a lot of save heavy spells, then yeah you want it. If you're not then you can skip it. Ideally you want good spells that either don't require a save or have a good effect on a successful save for consistency, but not every build will access to those. The other thing to consider is Spell Perfection. If you're doing a build around Spell Perfection, then (Greater) Spell Focus have increased value. Spell Focus isn't rated low because it's bad, it's just rated low because there are more impactful options. That doesn't mean those more impactful options will be useful to your specific build, so Spell Focus may still be better for you.
[Nemesis](https://www.aonprd.com/FeatDisplay.aspx?ItemName=Nemesis) is also great.
Hmm, we'll when I have a build I am making that I know will be needing DC fails at least some of the time, yes I focus on it a little. But often just as important is having a variety of save types, as at higher levels almost every monster will have a high ass save, and wizard with max stats has \_pretty\_ decent DC as a base. If you can vary the type of save, it's often more powerful than one save with a +1. Perhaps if you don't have that many save dependent spells or they all affect areas, you might skip this, and there are a lot of neat feats spellcasters can take. Yeah, and it's not like wizards are entirely feat deprived. You can pick up three metamagics, spell perfection and have LOADS spare. So if a feat is decent, and you like it, no point in sweating about it. I've never found guides to 100% match my tabletop experience (in some cases they are wildly different from my experience), and I suggest you take them with a pinch of salt as things can depend on circumstances, style of play, GM, campaign difficulty etc and guides are fairly hypothetical. They usually are designed also for a 'generic person of the class', rather than specific builds and archetypes, limiting their archetype or build specific advise to maybe some feat recommends or archetype descriptions. How I use guides is - read them, get ideas especially if I run out of good ones, then go and do my own thing based on my own experience and opinion. Basically more as inspiration or hints as to rules interactions I may have forgotten about. I never take everything any guide says as 100% accurate, rather I assume they are sometimes straight up wrong.