Difficulty is an option in some single player and co-op modes that allows a player to adjust the game after one's skill. Depending on what mode is being played, different difficulty levels will affect the game in different ways. For example, a higher difficulty level in the Subspace Emissary will make the enemies harder by giving them more HP and making their attacks stronger, while a higher difficulty level in Target Smash changes the stage's design into a more difficult one. Sometimes, unlockables such as trophies or stickers depend on the difficulty on which a game mode is cleared. In the Subspace Emissary, Stock Balls vary in number, from appearing in most levels in Easy to never appearing in Intense.
The setting appears for all games' Classic Modes (including Smash 64's 1P Game), Adventure Mode, Subspace Emissary, All-Star Mode and World of Light. Additionally, in Brawl, the setting is available for Boss Battles, and has been added to Event matches and Target Smash!!. However, the event matches in Super Smash Bros. Brawl and Super Smash Bros. 4 only have three difficulties (Easy, Normal, and Hard). Smash 4 also featured an entirely retooled difficulty scale for its Classic and All-Star Modes, as with Ultimate on its Classic Mode.
Difficulty levels in Smash 64 and MeleeEdit
- Very Easy (blue difficulty)
- Easy (green difficulty)
- Normal (yellow difficulty)
- Hard (orange difficulty)
- Very Hard (red difficulty)
The difficulty selection in Smash 64's 1P Game.
The difficulty selection in Melee's Classic Mode.
Difficulty levels in BrawlEdit
Easy (やさしい, Easy)
Normal (ふつう, Normal)
Hard (むずかしい, Hard)
Very Hard (とてもむずかしい, Very Hard)
Intense (ゲキむず, Extreme)
In Event Matches, only three difficulty levels are available: 
Easy, 
Normal, and 
Hard.
Difficulty scalingEdit
In The Subspace Emissary the difficulty corresponds to values used to influence various aspects of the mode, such as enemy damage, attack speed, health, attack knockback, or attack size. This is based on the simple equation , where is the base value, is the additional amount, and is the difficulty value. For example, with a difficulty value of 4 for a Primid that has a base HP of 10 and an additional amount of 1.4, its HP would be . There are five sets of difficulty values that an enemy can be assigned, meaning that a Primid later in a stage can be made stronger than those before it.
While the player can select one of five difficulties, there are actually 15 difficulties. There are two additional difficulties, or "sub-difficulties", below each standard difficulty that are chosen when the player uses a continue. The more continues that are used the lower the sub-difficulty goes, up to maximum of five decreases below the selected difficulty—this means with enough continues, a player can start on 
Intense and end up one sub-difficulty above Hard.
There are three different groupings of five sets used in different contexts: Subspace Emissary, Boss Battles, and the Classic Mode battle against Master Hand and Crazy Hand also incorporate these mechanics. As Boss Battles does not have continues, the sub-difficulty values go unused. Sets 4 and 5 are also unused; the majority of bosses use set 1 for the first six rounds and set 2 for the remaining, with the exceptions of Petey Piranha who uses sets 1, 2, and 3 for each respective third of the mode and Duon who uses set 1 for all rounds. Classic Mode allows for three sub-difficulty decreases instead of five. It additionally selects a different set for each difficulty except for Easy and Normal, which both use set 1 with set 4 going unused. For clarity the unused values for Boss Battles and Classic Mode are omitted in the following tables.
| Difficulty | Sets | ||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| -2
|
0 | 0.6 | 1.2 | 1.8 | 2.4 |
| -1
|
0.3 | 0.9 | 1.5 | 2.1 | 2.7 |
| Easy
|
0.5 | 1.1 | 1.7 | 2.3 | 2.9 |
| -2
|
1.7 | 2.5 | 3.3 | 3.9 | 4.5 |
| -1
|
2.1 | 2.9 | 3.7 | 4.3 | 5 |
| Normal
|
2.5 | 3.3 | 4.1 | 4.7 | 5.5 |
| -2
|
3.2 | 3.8 | 4.7 | 5.5 | 6.2 |
| -1
|
3.6 | 4.2 | 5.1 | 5.9 | 6.6 |
| Hard
|
4 | 4.8 | 5.5 | 6.3 | 7 |
 -2
|
5.5 | 6.1 | 6.7 | 7.3 | 8 |
| -1
|
6 | 6.6 | 7.2 | 7.8 | 8.5 |
| Very Hard
|
6.5 | 7.1 | 7.7 | 8.3 | 9 |
| -2
|
8 | 8.5 | 9 | 9.5 | 10 |
| -1
|
8.5 | 9 | 9.5 | 10 | 10.5 |
| Intense
|
9 | 9.5 | 10 | 10.5 | 11 |
| Difficulty | Sets | ||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | |||
| Easy
|
0.6 | 1.2 | 1.6 | ||
| Normal
|
2 | 2.6 | 3.2 | ||
| Hard
|
3.5 | 4 | 4.5 | ||
| Very Hard
|
5 | 5.7 | 6.4 | ||
| Intense
|
9 | 9.5 | 10 | ||
| Difficulty | |
|---|---|
| -1
|
1.2 |
| Easy
|
1.6 |
| -1
|
2 |
| Normal
|
2.3 |
| -3
|
3.6 |
| -2
|
4 |
| -1
|
4.3 |
| Hard
|
4.6 |
| -3
|
6 |
| -2
|
7.3 |
| -1
|
7.6 |
| Very Hard
|
8 |
| -3
|
10 |
| -2
|
10.2 |
| -1
|
10.6 |
| Intense
|
11 |
Difficulty levels in SSB4 and UltimateEdit
Difficulty levels were significantly overhauled in Smash 4. The game's retooled Classic Mode features the Fiend's Scale to determine the game's difficulty. In this system, the player is able to select an intensity from 0.0 to 9.0, with higher intensities leading to harder fights, but more rewards; the default intensity is 2.0 (which is free to start), and selecting other intensities requires some gold, with each 0.1 increment costing the player a set number of gold depending on the intensity. The system is identical to the Fiend's Cauldron intensity system from Masahiro Sakurai's previous game, Kid Icarus: Uprising, and it even uses the same titles.
Selecting an intensity lower than 2.0 also costs gold, with the amount increasing per decrement. Setting the Intensity to 5.1 or higher allows Master Core to appear at the end of the mode after the player weakens Master Hand and Crazy Hand.
| Intensity level | Picture  |
Picture  |
Numeric values | Cost per 0.1 increment | Starting cost |
|---|---|---|---|---|---|
| Effortless | 
|
|
0.0 to 0.9 | −5G | 100G |
| Easy | 
|
|
1.0 to 1.9 | ||
| Standard | 
|
|
2.0 to 2.9 | 8G | 0G |
| Tougher | 
|
|
3.0 to 3.9 | 12G | 80G |
| Challenging | 
|
|
4.0 to 4.9 | 15G | 200G |
| Heatin' Up | 
|
|
5.0 to 5.9 | 20G | 350G |
| Extra Spicy | 
|
|
6.0 to 6.9 | 25G | 550G |
| Infernal | 
|
|
7.0 to 7.9 | 45G | 800G |
| White Hot | 
|
|
8.0 to 8.9 | 95G | 1250G |
| Nothing Harder! | 
|
|
9.0 | N/A | 2200G |
The difficulty chosen - in addition to making the CPU opponents tougher and the prizes greater - determines what is faced at the end of the game, with higher intensities adding new foes to the mix. In both versions, the encounter is as follows:
| Inclusion | Intensity range |
|---|---|
| Master Hand | All Intensities |
| Crazy Hand | 3.0 and Up |
| Master Edges & Master Shadow | 5.1 and Up |
| Master Beast | 6.0 and Up |
| Master Giant | 7.0 and Up 7.5 and Up
|
| Master Fortress | 8.0 and Up
|
Every time the player loses, he or she is given the option to continue. If the player elects to continue, the intensity lowers by 0.5. Regardless of whether or not the player continues, some rewards attained in the Classic Mode will be lost, as will some gold on the Fiend's Scale.
The game's All-Star Mode and Event Matches, however, use the traditional difficulties, though only three are available: Easy, Normal, and Hard. Unlike in Brawl, however, the colors for Normal and Hard are yellow and red, respectively.
In Super Smash Bros. Ultimate, the intensity can no longer be initially increased past 5.0 in Classic Mode; however, the intensity can increase depending on the player's performance in each round. The more the intensity racks up, the more of the mural is shown. The intensity scale's affect on bosses will depend on certain characters. For example, Fox can only fight Crazy Hand if he's able to get the intensity high enough, but for characters like Mario or Simon, who have a different boss other than Master and Crazy Hand, the intensity will not add any additional bosses. Traditional difficulty settings can be found in the game's Adventure Mode: World of Light: Easy, Normal and Hard, with update 4.0.0 adding a Very Easy setting. (Hard was added in the game's day 1 patch, update 1.1.0.)
