Cruel mode

Cruel Melee, Cruel Brawl and Cruel Smash are Multi-Man modes in Super Smash Bros. Melee, Super Smash Bros. Brawl, and Super Smash Bros. 4 and Super Smash Bros. Ultimate, respectively. Like Endless mode, this mode challenges the player to defeat as many opponents as possible (Fighting Wire Frames in Melee, Fighting Alloy Team in Brawl, and Fighting Mii Team in Smash 4 and Ultimate), with no KO limit or time limit before the mode ends; high scores in this mode are recorded by the number of opponents defeated.

However, Cruel mode features a complete reversal of what is normally encountered in other Multi-Man modes. While all other modes give the opponents a low AI level and cause them to take high knockback, making them very easy to KO in one hit, Cruel mode instead gives all of the opponents a high AI level (making them very aggressive) and applies the high knockback modifier to the player, making them the one who is very easy to KO in one hit. In addition, no items will spawn at all in the mode.

With up to five opponents on-screen at once, all ganging up on the player and with any single one of their attacks being an easy OHKO, while the player must try to fight up to five aggressive high-AI opponents while only dealing regular knockback with their own attacks and without items to assist, attaining high scores in this mode is considered one of the toughest accomplishments in the game. Due to the relentless difficulty, players often have to resort to exploiting the AI; for example, in Cruel Melee, scores in the thousands can be obtained by exploiting an AI standstill bug, performed by standing absolutely still on the rightmost edge of the small right platform. This causes any CPUs, including the Wire Frames, to cease all movement and stand indefinitely unless the player is within attack range. In both Cruel Melee and Cruel Brawl, planking can be an effective strategy; stalling under the stage will often cause the Wire Frames or Alloys to self-destruct when attempting to edge-guard the player (as they still do not have any recovery special moves). In Super Smash Bros. 4, most possible exploits have been fixed as enemies will no longer follow the player if they jump far off the ledge, and will instead wait until the player gets back on stage. There are still some exploits that can help, a common one including using a fighter with large, horizontal hitboxes in their up special. Grabbing the ledge, dropping, double-jumping, then using the up special to grab the edge causing minor damage to the fighters on stage and occasionally tricks them into jumping off the stage and SD'ing. The most common fighter for this strategy is Lucina, as she specifically is able to complete two challenges at once in. Without AI exploitation, getting scores even higher than single-digit numbers is considered extremely difficult.

In Super Smash Bros. Melee

 * Defeat 5 opponents: Mr. Resetti trophy.

In Super Smash Bros. Brawl

 * Defeat 5 opponents: Red Alloy trophy.
 * Defeat 10 opponents: Liquid Snake sticker.

In

 * Play Cruel Smash once: Spiny Hat headgear.
 * Defeat 2 opponents: Shield Exploder Protection Badge equipment.
 * Defeat 4 opponents: Lion Hat headgear.

In

 * Defeat 1 opponent (Solo only): stage.
 * This will also challenge the player to defeat in order to unlock them, provided they have not been unlocked yet.
 * This challenge is immune to the Golden Hammer.
 * Defeat 8 opponents: Toadsworth trophy.
 * Survive for 1 minute as (Solo only): Mr. L trophy.
 * Defeat 4 opponents as (Solo only): Reaper trophy.
 * Defeat 8 opponents as (Solo only): Vampire Brawn Badge equipment.
 * This challenge is immune to the Golden Hammer.

In Super Smash Bros. Ultimate

 * Defeat 3 opponents (Solo only): Captain Falcon Challenge.

Trivia

 * The Super Smash Bros. Melee incarnation of this mode is infamous for its involvement in the Sonic and Tails Rumor spread by Electronic Gaming Monthly magazine as an April Fools' joke. The rumor suggested that after defeating 20 Fighting Wire Frames in a single round, the player would be challenged to defeat Sonic and Tails of the Sonic series, where victory would result in unlocking the characters.
 * In Super Smash Bros. Brawl, the track ' that plays during Cruel Brawl cannot be played from Brawls Sound Test, and it cannot be selected as music for custom stages. It would later become available in Smash 4'''s Sound Test.
 * In Super Smash Bros. Brawl's Cruel Brawl, some Fighting Alloys are given stronger handicaps than others. This can be seen even further by modifying their knockback values with hacks.
 * In Melee, 's Rest is strong enough to OHKO the wireframes in Cruel Melee.

Videos
Cruel Melee:
 * Ganondorf AI exploit

Cruel Brawl:
 * Jigglypuff Demonstration
 * Marth Demonstration
 * Mr. Game & Watch Demonstration
 * Toon Link Demonstration
 * Luigi Demonstration
 * Meta Knight Demonstration
 * Lucario Demonstration

Cruel Smash:
 * Opponent aggressiveness demonstration - inflicting 205% damage in the span of about 0.5 seconds