Hard Mode

Hard Mode is a mode featured in the Mario series that increases the difficulty level of the game. When playing in this mode, certain elements of the game are changed to reflect the difficulty, such as the enemy's strength.

Super Mario Bros.
After completing the main game in Super Mario Bros., the player is given the option to pick a world to play in "a new quest". At the title screen, the player can choose which world to start at by pressing before beginning Hard Mode. In this mode, all Goombas are replaced by Buzzy Beetles, and all enemies move faster; all of the elevator-style lifts are about sixty percent of their original size, while Fire Bars appear in all possible locations. The player still has the same amount of time to complete each level. Mario and Luigi gain no special powers in Hard Mode, and they receive no extra points when they defeat an enemy. Earlier levels in Hard Mode are the same as their harder clones; for instance, 1-3, which is an easier version of 5-3 in the normal game, is identical to it in Hard Mode. There is no reward for finishing the game in Hard Mode, and any subsequent playthroughs of the game will start over in this mode.

Super Mario Land
Hard Mode in Super Mario Land is unlocked after completing the main game, indicated by Mario's head replacing the Mushroom on the title screen. In this mode, more enemies appear in every level, and completing it unlocks a level select option.

Yoshi's Safari
Hard Mode in Yoshi's Safari can be played by holding, , , and pressing  at the title screen. In this mode, there is a slight change in dialogue; coloration is altered for the title screen, map screens for Light Realm and Dark Realm, and courses; bosses and enemy projectiles move much faster, time limits for each course are reduced by one minute (excluding Cornice Cave and Dark Sea), and the player earns double points.

Luigi's Mansion
After completing the main game for the first time in Luigi's Mansion, the quest can be restarted in the normal mansion or the "Hidden Mansion". In this mode, the Poltergust 3000 has 1.5x more power, making it easier for the player to capture regular ghosts and Portrait Ghosts; Luigi takes twice as much damage, his Flashlight freezes ghosts in half the time in the regular mansion, and Hearts are more difficult to find and are smaller than usual. A gold star appears on the bottom right-corner of the screen when playing in the Hidden Mansion. The player can switch between the regular mansion and the Hidden Mansion anytime they speak to Professor E. Gadd. There is no reward for completing the Hidden Mansion.

Mario & Luigi: Dream Team
In Mario & Luigi: Dream Team, Hard Mode is unlocked when the player completes the game on a file at least once.

When unlocked, an orange button with "START OVER IN HARD MODE" is shown on the file select screen at the bottom of the touch screen, which allows the player to start a new game file on Hard Mode. When selected, the player is given an option to chose which file will be chosen for Hard Mode; once the player creates a file on Hard Mode, it cannot be changed back to a normal file unless the player erases the file. A Hard Mode file has an orange label with "HARD" displayed on it.

In Hard Mode, enemies inflict much more damage and receive less, the timing on basic Jump and Hammer attacks is stricter, and the maximum amount of items the Bros. can carry is ten (wearing the Bottomless Gloves lifts this restriction in battles). Like the previous Mario & Luigi games, should the Bros. lose in a battle in Hard Mode, rather than having the option to restart it, they will automatically be taken back to the last save point. Giant Bosses have different attack patterns than on a normal file, and the recommended levels for facing bosses in the Battle Ring have increased by five. Upon beating the final boss in Hard Mode, the player gets to view a two-screened image featuring all the main characters and main bosses in the game.

Donkey Kong Country: Tropical Freeze
Hard Mode is unlocked in Donkey Kong Country: Tropical Freeze replacing Mirror Mode from the previous game after the player completes every single level in the game. When playing on Hard Mode, the player can select any of the four Kongs, but will only have one health, and cannot use any items in their inventory. Checkpoints will also not appear in the stage. Upon completing a stage in Hard Mode, it will be marked green on the world map.