Critical effects on 20/20 rolls with Advantage

Posted on September 5, 2014 by


Back in the old days, we played D&D with the Loremaster Critical Hit/Fumble charts. They added some nasty effects to the game, making it really deadly. Like, sever someone’s spine and leave them paralyzed for the rest of their lives deadly… I thought that it would be cool to introduce something similar to my game and see if the players bite. The idea is that on an attack roll made with Advantage that results in a double 20 roll, a critical effect is triggered. The player would then roll a percentage roll and the chart would generate the result. A double 20 on Advantage has a 1 in 400 chance of happening, so this is not very game breaking, btw. I wrote it so that it is easy to narrate for both spell effects and martial attacks. I may come up with a Fumble chart later, but I wanted to put this out there before my next home game.

Critical Effects

On a 20/20 Attack Roll made with Advantage, resolve all damage and effects due to the attack, then roll percentage dice and consult this chart to generate a Critical Effect:

01-10 Your attack knocks your target prone.

11-20 Your attack severely slows down your target. Its speed is halved for the duration of the encounter.

21-25 Your attack severely injures your target, causing it to suffer 3HP of damage at the start of its turn for the duration of the encounter.

26-30 Your attack causes your target to become exhausted (level 1). Any further successful attacks agains this creature will increase its exhaustion level by 1.

31-35 Your powerful attack frightens your target for the duration of the encounter.

36-40 Your potent attack severely impairs your target, its speed is halved and it is blinded for the duration of the encounter.

41-45 What a hit! You stun your target for 2 rounds!

46-50 Your attack destroys your target’s weapon arm (or if natural weapons, it’s main attack limb). It’s pain causes it to suffer Disadvantage on all attack rolls for the duration of the encounter.

51-55 Your attack disarms your target, sending its weapon flying 10 feet in a direction of your choice. If your target had no weapons, you push it back 10 feet in a direction of your choice instead.

56-60 You sever your target’s spine. It immediately falls prone and is paralyzed. If your target has no spine, the same effects apply. Narrate accordingly.

61-65 Your attack causes permanent mobility damage to your target. Its speed is reduced to 5 feet.

66-70 Your attack is so powerful it affects your target as if it were affected by a Confusion spell (PHB pg 224).

71-75 Your vicious attack rips through your target’s defenses, causing it to suffer  -5 to its Armor Class  for the duration of the encounter.

76-80 Your attack blinds your opponent and also causes it to become deafened for the duration of the encounter.

81-85 Your attack damages your opponent’s nervous system. It suffers disadvantage on any saving throw for the duration of the encounter.

86-90 Your attack severely dazes your opponent. It suffers disadvantage on any roll for the duration of the encounter.

91-98 You go in for the kill. Your opponent suffers vulnerability to all damage types you inflict on it for the rest of the encounter.

99 You instantly kill your opponent. No questions asked. Where did this burst of strength come from?

100 Your frightfully powerful attack instantly kills your opponent. If another hostile creature is within 5′ of it, your attack kills that creature as well. Your incredible victory will be spoken about for years to come.


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