Standard 5e Rules

When playing Dungeons and Dragons 5th Edition, wild magic surges occur when a sorcerer with the wild magic origin casts a 1st level or higher spell. When that happens, the DM can have the player roll a D20 and on a roll of 1, roll on the wild magic spell surge table found in the player's handbook.

Starting at level 14, sorcerers gain the Controlled Chaos ability which allows them to roll twice on the wild magic spell surge table and choose either.

With these rules, visit the Surge Table Generator with a count of 100 and either roll or use the Select Random button.

Shortcut: Generate a table with 100 spell surges and select 1 at random

Variant: Surge at 0

An alternative rule is to use a surge at 0 or less. This works by rolling 1D20 and subtract 1 for the spell being cast, 1 for any meta-magic modifiers, and then 0-3 at the DMs discression to represent fatigue, stress, or any other factors that limit your ability to tap into the weave safely.

For example, a level 2 sorcerer with the wild magic origin casts the 1st level spell Magic Missle. The DM gives the player a -1 to the wild magic spell surge roll, so when they roll a 5, the Magic Missile is cast without issue. Later in the game, the player goes to cast Magic Missile again, but this time the DM gives them -3 to the wild magic spell surge roll: 1 for the spell level, 1 for having previously cast a spell recently, and 1 for taking damage in a round of combat recently. When the player rolls a 3, they subtract the modifier, and end up rolling 0 or less, so they must then roll on the spell surge table.

Variant: Encounter Table

The spellweave is a mysterious thing and sometimes behaves consistently different because of unknown factors.

This variant encourages players to have a smaller subset of the wild magic spell surge table that is swapped out over time, location changes, and encounters.

For example, at the start of the day the DM may generate a spell surge table of 20 and all spell surge rolls use that smaller table for a period of time. Later in the day in-game, an encounter starts and the DM chooses to re-roll the spell surge table and that one is used going forward.

This variant can be especially useful if there is more than one source of wild magic spell surge rolls either because of player characters, non-player characters, or the environment they are in.

Variant: Items and Attunement

This rule variant can be used to make magic item use a little more risky, but easily accessible.

All player and non-player characters can more easily use magical items but at the risk of triggering a spell surge. The risk is decreased with attunement, but the cost in both time and resources to attune to a magical item is also increased. Additionally, magic items can only be attuned to a single creature, so using magical items attuned to other creatures is especially risky.

Additionally, attunement can be considered more permanent and creates a bond between the magic item and the wielder. Attunement may not be easily broken by creating short distance or time between the attuned and the item. Destruction of the item may also result in wild magic spell surges if the item was not depleated of charges or magic beforehand.

For example, a player finds a wand in the treasure hoard of stolen goods from a defeated band of goblins. The low-level player incorrectly identifies the wand as a Wand of Pyrotechnics and attempts to show off. The DM determines that the wild magic spell surge modifier is -3 because the player did not identify the wand, and the wand was attuned to another character from the whom the wand was stolen from. The player rolls a D20 that results in a 2, and then must roll a wild magic spell surge.