I'm quite new to this game so please could you help. At higher levels monsters generally seem to have a higher bonus to hit than most players have AC value, making rolling to hit almost unneccessary unless you roll a 1. I'm finding this turns the game into a game of ticking off the hit points untill one or other is defeated instead of a heoric battle. I know I could increase the AC of the players by adding many magical items but everything seems to develop as levels increase except AC (unless your a fighter). Am I missing something?
Thanks for your help.
According to the monster creation chart in the back of the Bestiary, the high attack bonus goes from +2 (at CR 1) to +30 (at CR 20). You'll need to increase your AC by about 1.5/level if you want monsters' primary attacks to miss the same percentage of the time.
I think the game is intended for characters to be hit less often at low levels, and more often at high levels.
Nope. You've got that pretty well down. After mid levels, your AC is really there to start stopping those lower iterative attacks. The full attack bonus attack is just going to hit.
However, you've got to remember that hit points aren't directly equivalent to "health points". Hit points are expressly an abstraction used to represent how healthy a character is at that moment and takes into account stamina, health, luck and training. So, those first few swipes by the terrasque aren't necessarily taking huge chunks out of the fighter's flesh, but wearing him down so that later swipes will start getting to the gooey center.
If your players aren't wanting to get hit, have them look into items/abilities that provide miss chances. The simplest are from blur and the like, such as a cloak of displacement. Miss chances can turn hits into misses at a flat percentage, not modified by the attacker's abilities.
You are correct and that is intentional - but you're not seeing the whole picture: first attacks at higher levels generally hit (unless the attacker rolls very low), but lower iteration attacks become progressively less likely to hit.
Exactly to make combat exciting and intense (and not last for hours) everybody has very good chances to hit on their big attack. Your AC starts mattering more and more for the lower iteration attacks. If you can only hit the first of your three attacks, then you're going to suffer - compared to the monster that hits with all of its attacks.
Also it is possible to get your AC to the point that the primary attack is likely to miss (hitting only about 20~35% of the time) without absolutely killing your ability to do anything else. However this is easiest done with either straight fighter, monk (surprisingly though it may sound) or specific combinations.
For arcane casters the best bet is generally to not be in a position to be hit, and to get as much miss chance, DR or whatever else they can manage for when something does swing at them.
Flanking characters need to set ways to prevent attacks on themselves.
A could metric for AC is to try and have your level +13 at low levels, and your level +15 after 10th level.
This is easy to surpass at low levels, everyones usually levels out between 6 and 10 and afterwards it does get harder, require more gear. The trick to AC is finances, always buy the cheapest AC increase.
+1 armor/shield bonus (1000)
+1 ring of protection (2000)
+1 amulet of natural armor (2000)
+2 armor/shield (+3000)
dusty rose prism ioun stone (5000)
+2 ring (+6000)
+2 amulet (+6000)
etc.
Of course, it is worth mentioning that lots of similar game systems use a primary defensive stat that scales with level instead. But if you did that, you would probably want to call it something other than Armor Class.
Making AC scale with level is also a very popular house rule, although it has far-reaching implications for the rest of the system. As such, it's best to leave well enough alone unless this really drives you nuts.
It took me a long time to come to terms with it as a rules-wonk.
AC is not all its cracked up to be. I mean, okay, you put 90% of your treasure pick/cash flow into upping your AC. You get something like 30 AC at level 7 with full plate, shield, ring, amulet, and decent dex/dodge. Enemies have to nat 20 to hit you. But...you still fall like a sack of potatoes to the lamest spells like hold person or conjure pit.
Even assuming that your worst danger is physical damage, and further assuming that it will all be physical damage (not fireballs) and none of those attacks are touch attacks (by the way, these are BIG assumptions) then an extra +1 AC is 5% less chance to be hit or 5% more health. Roughly. At level 7, assuming a 16 con and average HP rolls, a fighter will have 71 HP. An extra 2 con (belt of con) gives you 5 HP or 10% more HP for 4k vs. another +1 to your +2 armor (5k) or 6k for rings/amulet. And it just gets worse from there.
A decent AC is never something I'll say is irrelevant especially at low levels. But past your +1 items, maybe +2 or +3 armor, it is rapidly not worth it. You're better off putting your cash into cloak of resistance and taking Iron Will than Dodge.
Of course, ignore this all if you never play past level 6 or 7.
Also, I'll echo Mauril's statement about the Cloak of Displacement. Solid investment.
AC is like almost everything else in the game: you have to invest in it as you gain levels for it to stay relevant (and focusing most of your resources in one area leaves weaknesses in others). However, bonuses to AC are generally easier to come by than bonuses to attack rolls.
Armor, natural armor, shield, Dex, dodge, and deflection bonuses to AC (as well as others) are readily available from equipment, magic items, feats, and spells. There are more effects that stack (for most characters) on the AC side than on the attack side, as well.
Pretty much anyone that can wear armor (i.e., most non-tank combatants) can easily obtain an AC of 10 (base) + 11 (+5 mithral breastplate; 29,200 gp) + 5 (14 Dex and belt of incredible Dexterity +6; 36,000 gp) + 5 (ring of protection +5; 50,000 gp) + 5 (amulet of natural armor +5; 50,000 gp) + 1 (dusty rose prism ioun stone; 5,000 gp) = 37 before adding circumstance, dodge, haste, etc. bonuses. 170,200 gp is even slightly less than the recommended 25% of a 19th level character's total wealth for defensive items (even when considering the belt of incredible dexterity as a defensive item). Per Table 1-1 in the Bestiary, a CR 19 "High Attack" creature should have a total attack bonus of +29, or a 65% chance of hitting with their best attack; a CR 19 "Low Attack" creature, with a total attack bonus of +22, will only have a 40% chance of hitting with their best attack.
Characters who want to tank (without even considering a fighter with Armor Training) can obtain an AC of 10 (base) + 11 (+5 mithral breastplate; 29,200 gp) + 6 (+5 buckler; 25,165 gp) + 5 (14 Dex and belt of incredible Dexterity +6; 36,000 gp) + 5 (ring of protection +5; 50,000 gp) + 5 (amulet of natural armor +5; 50,000 gp) + 1 (dusty rose prism ioun stone; 5,000 gp) = 43 for 195,365 gp total (159,365 gp if counting the belt as something other than a defensive item). The same CR 19 creatures would have a 35% chance to hit for a "High Attack" creature and a mere 5% chance to hit for a "Low Attack" creature.
Fighters and monks can have even higher AC values. Judging from Table 1-1, tank combatants should probably have an AC around level + 18-22, while most other characters should probably be around level + 12-16. Values that are much higher or lower will either make things too easy or too dangerous for most encounters.
EDIT: Weird, but for some reason I'm not seeing some of my changes in the post, but when I edit it they do show up.