aha! okay so your attack roll is d20+proficiency+attack stat. The attack stat depends on what you're using. A dex weapon gets dex, a strength weapon gets strength mod, and a spellcaster gets whatever stat they cast with. So my lvl 10 rogue shakes out at d20+4+4 if he attacks with his daggers, and d20+4+2 if he slings a spell (roguelock dual class, his spell stat is CHA) damage rolls depend on the weapons used. again moving on the example of my rogue: a normal attack with a dagger would be 1d4. his main dagger does 1d6 fire damage (so: 1d4+1d6), and his offhand one does an additional 1d4 ice damage (1d4+1d4). As a rogue, he gets the Sneak Attack feature, which deals bonus damage to enemies under certain conditions (they are detailed in the decription of the feature). You also add the bonus of the relevant stat, in this case, +4 from DEX. If you have an additional bonuses, like a magical weapon that does +1 you add that, too. So petric, doing sneak attack with Flametogue does 5d6+1d4+1d6+4. If he pulled the same move with Seabird it'd be 5d6+1d4+1d4+4 A spellcaster is a bit more complicated depending on the spell. Again, on example of petric, casting eldritch blast: to attack: 1d20+4+2. If he hits, he rolls 1d10. the damage type is force. Some spells you don't have to roll attacks for. For example, Toll The Dead (a cantrip) requires your target to make a save. For that, your target rolls a d20+relevant stat (in this case: WIS). if the result is lower than your spell save (8+prof+Stat mod) the target takes the hit. In this case, the target takes 1d8 necrotic damage (or 1d12 if the target wasn't at full health anymore). Spell damage scales with the character/casting level, so Toll The Dead at lvl 17 does 4d8/4d12 damage instead. The spell you cast should say in its description if the target needs to make a safe or if you roll to hit. for the really complicated version: Petric has Green Flame Blade as a cantrip, which he can trigger upon hitting a target. All normal effects of the attack still apply, so if he uses it on a sneak attack with flame tongue, he still gets 5d6+1d4+1d6+4 HOWEVER at his current level the spell allows him do an additional 1d8 to the target AND 1d8+CHA to another target within 5 ft of the first. thus turning his attack into 5d6+1d4+1d6+1d8+4 to one target and 1d8+2 to a nearby one. This 'splash' damage hits automatically and does not require a second attack roll. Details like that are again usually listed in the spell description.
To hit something with a weapon attack, you roll a d20. To that number, you add a couple things: 1) Dex or strength modifier. You add your dex modifier to most ranged weapons. Your strength modifier is added to other weapons. ETA You add either to finesse weapons. (Thank you for clarifying, @Helen of Boy ) 2) Proficiency bonus. Your character might be proficient in certain types of weapons due to race/class/background. If they are, you add your proficiency bonus. The default character sheet has a place for your weapons. One column says attack bonus; that's where you can write down the sum of any modifiers you add to an attack with that weapon. For damage rolls, you roll the dice indicated in the weapon's information, which usually includes a +# that you add to the roll. My character is proficient in the use of longsword, so when she attacks with it I roll 1d20 and then add her strength modifier (+5) and her proficiency bonus (+3). If it beats the enemy's AC, I roll 1d8 and add 5 to that for damage. To add to @TheOwlet's bit about reactions, I was Extremely disappointed to learn that you only get one reaction per round.
i striaght up forgot about proficiencies not automatically applying because petric hasn't used anything he's not proficient in since he got his hands on his knifes. Stabby boy. Oops.
If you xast a spell of your classes spelllist, you're prof im it. Iirc, house rules on whether you can cast non-list spells at all (exception for non-list spells you acquire through racials or feats or incantations)
To be more clear, even, you also get proficiency bonus to any spell you get from racial bonuses or feats or the like, where applicable. Not quite! You may choose between strength and dex for finesse weapons. Also, despite having range, a thrown weapon uses your strength, unless it also has finesse (like daggers do).
can i just say that this is a fucking ridiculously obscene damage roll and my mildly dyscalculic bitch brain is sitting in a corner sobbing?
.... if i pull him through to level twenty, his damage roll for this exact situation will be 10d6+1d4+1d6+3d8+5 to the main target and a splash of 3d8+CHA (whatever that mod may be at the time) and mind you, if I crit, i get to double the rolled ones, so 2(10d6+1d4+1d6+3d8)+5 or y'know. use the Death Strike feature, which Rogues are glass canons but they are very good at the murder. But yeah, i am very happy that i play online and r20 calculates such damages for me, everything else is suffering.
I play meatspace and at least once a night I roll an absurd amount of die for my warlock and then sit and squint going "numbers" until someone helps me so basic addition.
Both my groups have at least one mathematician, and myself, who has long since learned to add dice numbers together quickly, and we do a lot of adding for other people when necessary.
Bard: Who fills a Bag of Holding with bananas? GM: It's not a Bag of Holding. It's a Bag of Holding Bananas.
GM: sets up what seems like a great trap-- a narrow hallway with two juggernauts, constructs that specialize in trampling, closing in on the party from either end bard: unbeknownst to GM, just got group Spider Climb juggernaut: has 5-foot reach fight: cheesed we also cast grease and lit it on fire, so they were unstoppably rolling towards... each other, on a slippery flaming floor. womp womp.
really any mid-to-high level caster can completely derail fights, especially once you start getting the group spells. in the adventure path i ran, the party was sneaking into the Big Bad's fortress in an attempt to assassinate and supplant him. there were like 4 separate phases, tons of cool and interesting fights, some tricky traps... but the mesmerist had just gotten mass invisibility. and their logic was "if all goes well, we'll be all of these people's bosses tomorrow. we shouldn't kill anyone unless we absolutely have to, we want to keep this operation going!" which! very fair, very smart! but also, they skipped an entire phase of the dungeon. i had to end that game after like 45 minutes, because they had skipped about three weeks playtime worth of dungeon and i wasn't prepped for anything that far in advance.
My partner's rogue sidestepped what was supposed to be a big group fight demonstrating our ability to survive the area we were going to enter by going "You said I had to beat you, you didn't say how" and then challenging the lord to a riddle contest, then going "wtf, not cool, I refuse to fight" when this didn't work. We were allowed in anyway, probably out of a combination of exasperation and spite on the lord's part (and sheer exasperation on the DM's).
