Critical Hit

In a d20 system, attacks are rolled on a 20-sided die, so rolling a 20 is considered a "critical success". In some games, instead of critical hits dealing more damage, they can instead do special effects. Here's several tables to determine those sorts of effects. There are four types of tables here, for the various types of weapon damage: 'bludgeoning', 'slashing', 'piercing', and 'magical'. Calling for a result from the table named as the damage type has a 10% chance of something unique instead of a standard critical multiplier for that weapon. The tables named with a "-special" after the damage type just have the special effects. Use whichever one best fits your play style (wanting 'normal' criticals to happen most of the time, or having all criticals be replaced with 'special' occurrences.

Bludgeoning
[bludgeoning-special]

Magical
9,weapon deals damage as a normal critical 1,[bludgeoning-special]
 * bludgeoning

1,opponent's hand is [bludgeoning-adj]; weapon does standard damage and opponent gains -1 to attack 1,opponent has 1d4 fingers broken; weapon does standard damage and opponent's hand is now useless until healed 1,opponent's toe is [bludgeoning-adj]; weapon does standard damage and opponent is reduced to one half movement speed 1,opponent's foot is [bludgeoning-adj]; weapon does standard damage and opponent is reduced to one quarter movement speed 1,opponent's leg is [bludgeoning-adj]; weapon does standard damage and gives an automatic trip attempt 1,opponent's leg is [bludgeoning-adj]; weapon does standard damage and opponent is reduced to one half movement speed 1,opponent's knee is [bludgeoning-adj]; weapon does standard damage and opponent is reduced to one quarter movement speed 1,opponent's hip is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's hip is [bludgeoning-adj]; weapon deals standard damage and gives an automatic trip attempt 1,opponent's knee is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's knee is [bludgeoning-adj]; weapon deals standard damage and gives an automatic trip attempt 1,opponent's wrist is [bludgeoning-adj]; weapon deals standard damage and opponent's primary arm is disarmed 1,opponent's wrist is [bludgeoning-adj]; weapon deals standard damage and opponent's off-hand arm is disarmed 1,opponent's wrist is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's wrist is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's elbow is [bludgeoning-adj]; weapon deals standard damage and opponent's primary arm is disarmed 1,opponent's elbow is [bludgeoning-adj]; weapon deals standard damage and opponent's off-hand arm is disarmed 1,opponent's elbow is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's elbow is [bludgeoning-adj]; weapon deals 1d4 Dex damage instead of standard damage 1,opponent's shoulder is [bludgeoning-adj]; weapon deals standard damage and gives an automatic trip attempt 1,opponent's shoulder is [bludgeoning-adj]; weapon deals standard damage and opponent gains -1 to attack 1,opponent's gut is [bludgeoning-adj]; weapon deals standard damage, and opponent must make DC 10 plus damage dealt Fort save or fall prone 1,opponent's ribs are [bludgeoning-adj]; weapon deals standard damage, and opponent is stunned for 1 round 1,opponent's ribs are [bludgeoning-adj]; weapon deals standard damage, and opponent gains -2 to attack 1,opponent's head is [bludgeoning-adj]; weapon deals standard damage and opponent is stunned for 1 round 1,opponent's head is [bludgeoning-adj]; weapon deals 1d4 Int damage instead of standard damage 1,opponent's head is [bludgeoning-adj]; weapon deals standard damage and provides automatic trip attempt 1,opponent's face is [bludgeoning-adj]; weapon deals 1d6 Chr damage instead of standard damage. Opponent's bite attack is at -2 to hit 1,opponent's face is [bludgeoning-adj]; weapon deals standard damage, and opponent is blind for 1 round
 * bludgeoning-special

1,crushed 2,smashed 3,pummeled 4,pulverized 5,bashed
 * bludgeoning-adj