Sprites are an interesting choice for a familiar. They have a few strong features, such as their Invisibility and their poisoned ranged attacks. They have low HP, but all familiars do... They have high AC though and their ability to fly out of range and hide (Stealth+8!) makes them pretty durable. Their Shortbow attacks in particular are what I want to focus on though. They always have a decent chance to either poison an enemy (which gives Disadvantage for 1min!) or flat-out knock enemies unconscious even at full HP. And for those that aren't aware, in the Find Familiar spell it says, "In combat, it rolls its own initiative and acts on its own turn." You don't have to sacrifice your actions and damage for it to attack, which is a benefit over Beastmasters.
Note: Invisibility gives the Sprite Advantage on its first attack each fight too, so that's amazing for starting off fights with an almost guaranteed poisoned or slept enemy.
We only need 2 levels of Warlock to be useful with Agonizing Blast always at our fingertips. Warlock 3 gives us the Sprite, but after that we can multiclass and it won't hurt our consistent damage. What we want to do is find things that can affect enemy saves to help our Sprite land its poison/sleep. Bard's Cutting Words doesn't even work for it. But there are a couple things, such as Divination Wizard's Portent ability at level 2, as well as Wild Magic Sorcerer's Bend Luck feature at level 6, that can force these enemies to fail their saves. There's also the Contagion spell that gives Disadvantage on CON checks with Slimy Doom, but that's pretty high up the Cleric list (level 9 Cleric minimum). So, forgetting Cleric for the time being, we can try this:
Pact Warlock 3/Div Wizard 2/Wild Magic Sorcerer 6
1-3 Warlock - Agonizing Blast for our own damage and Pact for Sprite. If the average enemy AC is 13 for these early levels, then the sprite has a 70% chance to hit them with its +6 to attack. If the average enemy CON is +1 for these early levels, then the sprite has a 45% chance to poison them and a 20% chance to sleep them.
4-5 Div Wizard - Pick up Portent. If ~eAC = 14, then 65% chance to hit. If ~eCON = +2, 40% chance to poison, 15% chance to sleep. It's near impossible to calculate Portent's influence on these percentages, but I've never had more than 20 attack rounds in a day. If even one of those attacks or saves is replaced by a Portent, then you can boost those numbers by 5%+. It can force a sleep when you need it most if you roll very low on the Portent rolls. I will say that you want to aim for <5 CON saves, and with a +2 ~eCON, you really need 3 or less. With 2 Portents a day, you have a 15%+15% = 30% chance that you'll have at least one Portent roll that's 3 or less.
6-11 Wild Magic Sorc - Here's where we see the biggest boost to this build. Haste and Bend Luck bump our percentages significantly, helping our hit rate rise and boosting the average save fail by 2.5/20=12.5%. If ~eAC = 15, 60% chance to hit = 40% chance to miss = 40%*40% to miss 2x in a row in one round = 16% chance to miss both attacks = 84% chance to hit with at least one of the shots each round. If ~eCON = +3, 35%*+12.5% = 47.5% chance to poison each attack = 52.5% chance to make the save = 52.5%*52.5% chance to save 2x in a row in one round = 27.6% chance to make both saves in a row = 72.4% chance to poison with at least one of the shots each round. If ~eCON = +3, 10%+12.5% = 22.5% chance to sleep one attack and 10% chance to sleep another (only one reaction per turn for Bend Luck) = 77.5% chance to make the save once and 90% chance to make the save second = 77.5%*90% chance to save 2x in a row in one round = 69.8% chance to make both saves in a row = 30.2% chance to sleep with at least one of the shots each round. Holy mother
ing shitballs. This doesn't even account for Portent's flat 5%+ boost!
At level 11, this build is undeniably powerful, with high percentages of success. But even pre-11, there is a lot of fun to be had by a 2HP Sprite knocking a large troll unconscious on the first round of a fight. And like I said before, you're already mechanically-capped at Warlock 2 with Agonizing Blast anyway. Why not throw in an extra 30% chance to sleep big enemies? I'd laugh so hard when the DM is forced to waste a dragon's Legendary Resistance on a Sprite's Shortbow.
Note: Invisibility gives the Sprite Advantage on its first attack each fight too, so that's amazing for starting off fights with an almost guaranteed poisoned or slept enemy.
We only need 2 levels of Warlock to be useful with Agonizing Blast always at our fingertips. Warlock 3 gives us the Sprite, but after that we can multiclass and it won't hurt our consistent damage. What we want to do is find things that can affect enemy saves to help our Sprite land its poison/sleep. Bard's Cutting Words doesn't even work for it. But there are a couple things, such as Divination Wizard's Portent ability at level 2, as well as Wild Magic Sorcerer's Bend Luck feature at level 6, that can force these enemies to fail their saves. There's also the Contagion spell that gives Disadvantage on CON checks with Slimy Doom, but that's pretty high up the Cleric list (level 9 Cleric minimum). So, forgetting Cleric for the time being, we can try this:
Pact Warlock 3/Div Wizard 2/Wild Magic Sorcerer 6
1-3 Warlock - Agonizing Blast for our own damage and Pact for Sprite. If the average enemy AC is 13 for these early levels, then the sprite has a 70% chance to hit them with its +6 to attack. If the average enemy CON is +1 for these early levels, then the sprite has a 45% chance to poison them and a 20% chance to sleep them.
4-5 Div Wizard - Pick up Portent. If ~eAC = 14, then 65% chance to hit. If ~eCON = +2, 40% chance to poison, 15% chance to sleep. It's near impossible to calculate Portent's influence on these percentages, but I've never had more than 20 attack rounds in a day. If even one of those attacks or saves is replaced by a Portent, then you can boost those numbers by 5%+. It can force a sleep when you need it most if you roll very low on the Portent rolls. I will say that you want to aim for <5 CON saves, and with a +2 ~eCON, you really need 3 or less. With 2 Portents a day, you have a 15%+15% = 30% chance that you'll have at least one Portent roll that's 3 or less.
6-11 Wild Magic Sorc - Here's where we see the biggest boost to this build. Haste and Bend Luck bump our percentages significantly, helping our hit rate rise and boosting the average save fail by 2.5/20=12.5%. If ~eAC = 15, 60% chance to hit = 40% chance to miss = 40%*40% to miss 2x in a row in one round = 16% chance to miss both attacks = 84% chance to hit with at least one of the shots each round. If ~eCON = +3, 35%*+12.5% = 47.5% chance to poison each attack = 52.5% chance to make the save = 52.5%*52.5% chance to save 2x in a row in one round = 27.6% chance to make both saves in a row = 72.4% chance to poison with at least one of the shots each round. If ~eCON = +3, 10%+12.5% = 22.5% chance to sleep one attack and 10% chance to sleep another (only one reaction per turn for Bend Luck) = 77.5% chance to make the save once and 90% chance to make the save second = 77.5%*90% chance to save 2x in a row in one round = 69.8% chance to make both saves in a row = 30.2% chance to sleep with at least one of the shots each round. Holy mother
ing shitballs. This doesn't even account for Portent's flat 5%+ boost!At level 11, this build is undeniably powerful, with high percentages of success. But even pre-11, there is a lot of fun to be had by a 2HP Sprite knocking a large troll unconscious on the first round of a fight. And like I said before, you're already mechanically-capped at Warlock 2 with Agonizing Blast anyway. Why not throw in an extra 30% chance to sleep big enemies? I'd laugh so hard when the DM is forced to waste a dragon's Legendary Resistance on a Sprite's Shortbow.
