Your innate magic comes from the wild forces of chaos that underlie the order of creation. You might have endured exposure to some form of raw magic, perhaps through a planar portal leading to Limbo, the Elemental Planes, or the mysterious Far Realm. Perhaps you were blessed by a powerful fey creature or marked by a demon. Or your magic could be a fluke of your birth, with no apparent cause or reason. However it came to be, this chaotic magic churns within you, waiting for any outlet.
At 3rd level, your spellcasting becomes unstable, and can unleash surges of untamed magic. After you cast a sorcerer spell of 1st level or higher, you roll a d10. If you roll a 1, roll on the Wild Magic Surge table to create a magical effect. If that effect is a spell, it is too wild to be affected by your Metamagic, and if it normally requires concentration, it doesn't require concentration in this case; the spell lasts for its full duration.
Additionally, whenever you roll a natural 1, you roll on the Wild Magic Surge table twice, and the DM picks which number to use. Whenever you roll a natural 20, you roll on the Wild Magic Surge table and can choose whether or not the effect happens.
Starting at 3rd level, you can manipulate the forces of chance and chaos to gain advantage on one attack roll, ability check, or saving throw. Once you do so, you must finish a short or long rest before you can use this feature again.
Whenever you roll on the Wild Magic Surge table, you regain the use of this feature if you have already used it.
Starting at 6th level, you have the ability to twist fate using your wild magic. When another creature you can see makes an attack roll, an ability check, or a saving throw, you can use your reaction and spend 3 sorcery points to roll 1d4 and apply the number rolled as a bonus or penalty (your choice) to the creature's roll.
At 14th level, you gain a modicum of control over the surges of your wild magic. Whenever you roll the d10 to determine if you need to roll on the Wild Magic Surge table, you roll twice and use either number.
Additionally, whenever you roll on the Wild Magic Surge table to determine the effect, you can roll twice and use either number.
Beginning at 18th level, the harmful energy of your spells intensifies. When you roll damage for a spell and roll the highest number possible on any of the dice, choose one of those dice, roll it again and add that roll to the damage. You can use the feature only once per turn.