How to understand hit percentages?

[pyremind]

So, on an av fight I'm finding my hit percentages are very often 50-65%. The only time I get "sure hits" are when I've got the high ground and shooting, or I'm surprising enemies, or whatever..

But I really hate taking shots when it's basically a coin toss. Should I be? Or should I be tryin g to find more advantage some other way? Or am I under leveled?

Where can I see the numbers that created that percentage?

[CiZerin]

On right side of screen there is a button with arrow. Click it an you can see combat log.

[Gregorovitch]

Attack Roll bonus (i.e. what's added to your D20 roll) = Ability Modifier + Proficiency + Enchantment/Item Bonus + Class Features

That goes up against (in the case of simply swinging a sword) the targets AC. E.g if your attack roll bonus total is 10 and the target has an AC of 20 then to hit it you have to make D20+10 = 20. That is a 50% chance close enough.

Different types of attack go up against different types of defences (for example a fireball goes up against reflex saving throws and fire resistance) but the principle is always the same.

It follows that to improve your chance of hitting the target you try to improve your attack roll bonus because this shifts the D20 roll in your favour. The list of things to look at are listed in that formula above. For example your cleric can cast Bless on the party (an enchantment) which IIRC grants them a +1 to attack rolls. A +1 on a D20 roll = +5% chance to hit. That's why Bless is considered a kick arse spell.

If you study the combat log and expand the details of any one swing you will see the calculation set out, how exactly your attack roll bonuses were added up. Obviously knowing all this is very important when picking level up options and choosing your gear.

[not harvey]

As someone with hundreds of hours on DOS2, and 0 experience with DND, I was trying to work out the same thing. The answer is quite disappointing imo;

When you attack, there are (up to) 3 dice rolls.

You roll to see if you hit, this is based on your primary stat which only effects hit chances (eg.. charisma, intelligence...), but is ALSO reduced by enemy armor, so rather than actual armor, armor is more like a dodge chance.

You roll for damage if you hit.

The enemy rolls to resist statuses if the attack has them (saving throw), the stat they use for the roll is mentioned on the ability tooltip.

Basically just dice rolls all the way down, there is little way you can plan for any of it, except to pump as many points into your primary stat, I guess.

Much more frustrating than just a basic 95% hitchance against most enemies, with armor and stats only effecting damage and not making you miss all the time.

[Zeel Ara]

That's how d20 systems work.

https://roll20.net/compendium/dnd5e/Rules:Combat?expansion=0#toc_31

[Gregorovitch]

Originally posted by not harvey:

Basically just dice rolls all the way down, there is little way you can plan for any of it, except to pump as many points into your primary stat, I guess.

Your primary stat is obviously important but that's just one part of it, there are many other ways to improve your attack rolls. That's what the game is about, it's a bout manipulation the D20 rolls in your favour, loading the dice so to speak.

It's like backgammon. Bad backgammon players think they lose 'cos they get unlucky rolls. Good backgammon players pocket their money and politely enquire if their victim would like another game.

[Drake]

The D20 philosophy is that a a failed attack check doesn't mean a miss, it means it didn't do damage. What I mean by that is that when you fail an attack check, roleplaying wise it can mean it got evaded, blocked, missed, didn't penetrate armour or other similar failures.
Taking damage is the worst possible outcome and it is very lethal.

By default, the hit rate is 50% (you need to score a 10 on a d20 to hit) then each bonus point in attack equals +5% and each point in AC over 10 for the defender translate to -5%.
So it does go down very fast, and you need you stack attack bonuses to keep it up.

[TowerWizard]

On the Paper doll, under your weapon slot, there is a number that shows how much of a bonus you get with your to hit roll.

It is broken down into sub cathegories.

Bonus from stats (strenght, dex...)
Proficiency bonus
Bonus from magic weapon
Roll bonus

wait... What is a "roll bonus"?

Edit: I think it is from being Blessed by an Elixir of Heroism. Does that mean that the duration for the Bless is until the next long rest, even if the Blessed icon is only present for 10 rounds?

[wei270]

there is enemy AC, then there is your Roll 1 D 20 + any other modifier you have some + some -, since the roll is a D 20 each +1 is +5% . Advantage is difficult to calcuate. if you have 50% to hit, having advantage and taking the higher of the two you chance to hit is around 75%. if you are 80% to hit, advantage give you 96%.