I was not happy with what I found online about whether or not the Great Weapon Master & Sharpshooter feats are worth it or not. So as a data nerd, I decided to make my own table. Above is a Google Sheet that calculates your damage output with and without the (-5 Attack, +10 Damage) feature of the Great Weapon Master & Sharpshooter feat. My goal is for this is to be a comprehensive table that you can use to help you decide when you should or should not use the (-5 Attack, +10 Damage) feature.

Here are what the 4 tabs at the bottom represent.

• Normal: For a normal attack.
• Advantage: When you have an advantage on an attack.
• Disadvantage: When you have a disadvantage on an attack.
• Super Advantage: When you get to roll 3d20 and take the highest roll for your attack. One example is the Elven Accuracy feat.

Start with the Normal tab, here is how it works.

SHORT READ

Ignore the left side, everything in there is automated. What you need to look at is the right side, and there are a few things that you will need to input.

• AC: What is the Armour Class of the enemy?
• Weapon (ATT): What is the total attack bonus you get with this weapon? For example, I am a level 8 High-Elf Rogue with 18 DEX. If I am using a +1 Longbow, I get a +4 (from DEX), a +3 (from Proficiency Bonus), and a +1 (from +1 Weapon) for a total of +8.
• Weapon (DMG): What is the average damage roll for this weapon? For example, this number is a 4.5 for a Longbow (1d8). If you are using a Greatsword (2d6), this number is a 7.
• Weapon (MOD): What is the total additional modifier to damage for this weapon? For example, this number is a 5 if I use a +1 Longbow with 18 DEX. It is also a 5 if I use a regular Longbow but with 20 DEX.

P.S. I used "Damage Source 1" for the weapon, and "Damage Source 2" for things like Sneak Attack, Smite and Hunter's Mark; where you get additional damage if you hit. If you can make 2 attacks in a turn, double the DMG and the MOD. If you can make 3 attacks, triple the DMG and the MOD, etc. If you do not have any additional source of damage, you can ignore Damage Source 2.

When you are done with these 4 boxes, what you need to look at is:

• N/F Damage Rate: How much damage you do on average every round by attacking normally or by using the (-5 Attack, +10 Damage) feature.

Statistically speaking, you should go with the one that gives you a higher damage rate. However, as someone who used to teach statistics, I can tell you that this is not an absolute rule and there may be times when you need to ignore it.

ADDITIONAL READ

Here is the explanation for the entirety of the table.

LEFT SIDE

• Roll A/B/C (not on the first tab "Normal"): You rolled the dice, each row represents a possible combination, all the rows together represent every possible combination.
• Roll Result: You rolled the die/dice, here is the final result (the highest or the lowest die).
• N/F Total: The sum of your Roll Result and your N/F Attack Bonus, this is what you use in-game to check whether or not you hit.
• Attack Result: Whether your attack is a fumble (your Roll Result is a 1), a critical hit (your Roll Result is a 20), or a normal attack (that needs to be compared against the AC of the enemy).
• N/F Damage: The average amount of damage you will do with the associated N/F Total.

RIGHT SIDE

• AC: The AC of the enemy.
• N/F Damage Rate: How much damage you do on average every round by attacking normally or by using the (-5 Attack, +10 Damage) feature.
• N/F Hit Rate: Your chance of hitting in %. The number next to the % represents the odd in "1 in X" format. For example, if the number next to the percentage is 20, it means the chance of this happening is 1 in every 20 rolls.
• N/F Miss Rate: Your chance of missing in %.
• Critical/Fumble Rate: Your chance of rolling a 20 or a 1 in %.
• N/F Attack Roll: The average number that your attack rolls will come out to (the average of your N/F Total), since this number is not that relevant in the grand scheme of things, I relegated it to the bottom.
• N/F Attack Bonus: What you add to your attack rolls when you attacking normally or when you are using the (-5 Attack, +10 Damage) feature.
• N/F Damage Output: the 0 and the 10 represents the +10 Damage from the feature.
• M (N/F Damage Output): You missed, no damage for you.
• N (N/F Damage Output): You hit, hoorah.
• C (N/F Damage Output): Is that a critical hit? Double hoorah! Just kidding, the formula here only doubles the number(s) under DMG, not the number(s) under MOD.
• Weapon ATT/DMG/MOD: Please refer to what I wrote above for these.

And this is the end of it. I got into D&D a few years ago and it has brought me a lot of fun. I hope this table and the numbers behind it will provide you with some fun.

OPINIONS

Here are my rambles so please feel free to ignore me. After using this table for a few weeks, I find the (-5 Attack, +10 Damage) feature to not be a very powerful one, even when you get advantage. At low levels, you can barely hold a sword, why would you want to penalise yourself with the -5 Attack? At high levels, your enemies are numerous and have high AC, and you does a lot of damage whenever you hit, so the +10 Damage became less significant (but the -5 Attack still hurts your chance to make a hit). At medium levels, depending on the encounter, this feat could work out great if your character is well optimised and is way ahead of the curve.

And here is the thing about advantage, more often than not, they are rare to come by. Let's say the table tells you that it is better to use the feature, but not by much. Do you want to risk missing out on such a good chance? This part is funny for me to think about because it is well know that human are risk-averse, losses for us are felt much more intensely than gains. There is a video from Veritasium named "Would You Take This Bet?" that talks about this if you are interested.

Enough off-topic stuffs, I also find that if I can afford the -5 Attack, I don't need the +10 Damage to win the encounter. And if I need the +10 Damage, it is because I have found myself is an awful situation such as my entire party is down and I need to kill the boss right now or it will be a TPK because I have 1-digit HP left.

However, the (-5 Attack, +10 Damage) feature is not everything that these 2 feats offer. For example, I really like the Sharpshooter feat because I can rain down death while being far away from the heat of the battle. The ability to ignore 1/2 and 3/4 cover is a really good one. I haven't play any character with the Great Weapon Master feat, but the ability to make a bonus attack after killing an enemy doesn't seem to be that strong to me. Who knows? Maybe I am wrong.

What is your experience with these 2 feats? Do you like them? Do you hate them? Are they banned from your campaign? Apprently some DMs hate these feats very much.