Difficulty refers to how challenging the gameplay is. Terraria has different forms of difficulty.
- The actual Difficulty mode is a character setting selected during character creation. On the 电脑版, there are four options: Journey, Classic (Softcore ), Mediumcore and Hardcore, with Journey Mode being exclusive to the 电脑版, while the other modes are all available on the 主机版、 前代主机版、和 移动版, all modes changing the penalty upon death. Journey characters start with extra equipment and can only be played on journey worlds. Classic characters drop coins. Mediumcore characters drop items on death, and Hardcore characters cannot respawn, and drop all items on death. Once a character has been created, its difficulty cannot be changed. On the , there are no options, and all characters are created as Classic characters. 版
- Another form of difficulty is world modes. On the 电脑版, players may choose between Journey, Classic, Expert, and Master when creating a new world. Journey and Master Mode are exclusive to the 电脑版, with the rest being available on the 主机版和 移动版. However, the 前代主机版和 only have normal mode due to not having the 1.3 update. This is a separate setting that applies to the world, rather than the character, and similarly cannot be changed once the world has begun generating. 版
- A third form of difficulty is the transition from Pre-Hardmode to Hardmode, which also applies to the world. This is a gameplay advancement and is thus non-optional.
Journey Mode is unique, as the player may choose and change game difficulty whenever they wish. Journey Mode also includes additional tools such as godmode, item duplication, time and weather control, and the ability to control enemy spawns. The player must choose Journey on both the character and world creation menus to utilize it.
Classic characters drop half (3/4) (all) of their coins when they die, which can be retrieved upon respawning, but may also be collected by other players in multiplayer or by enemies in 专家模式. Classic characters respawn at their spawn point, 7 / 15 (15 / 30) seconds after death on singleplayer / multiplayer, respectively.
Mediumcore characters drop all of their items upon death, including all coins and ammo. These can be retrieved upon respawning, but any items may also be collected by other players in multiplayer and coins by enemies in Expert and Master Mode. Mediumcore characters still respawn at their spawn point, 7 / 15 (15 / 30) seconds after death on singleplayer / multiplayer, respectively.
The natural comparison here is to Minecraft, where this is the default behavior on death. There are, however, significant differences:
- Terraria's equipment is much more varied and individual than Minecraft's; while keeping spares or "second best" in a go-chest can help, there are some items that are not easily duplicated, and a few that come "one to a world".
- Item despawning behavior is very different; in Terraria there is no time limit, but items can despawn if too many other items accumulate in the world. This is not usually an issue unless the player has an automated farm running, or perhaps fights a major invasion before retrieving their dropped items.
- Likewise, the classic Minecraft terror of losing one's items to lava is significantly weakened, partly because of portable storage such as the Piggy Bank, but also because only the most commonplace items (Gray and White Rarity) are vulnerable to destruction by lava. In practice, this generally means coins, building blocks, ammunition, and other sundry supplies are destroyed, but use of an Obsidian Skin Potion makes recovering everything else fairly straight forward. Keeping a spare Void Bag and perhaps a Treasure Magnet at the player's home base can make it almost trivial.
- 娱乐模式: This is an easier mode, that gives the player extra items on the start, allows duplicating items, and allows making the game easier. See Journey Mode for a more complete list.
- 经典 / 正常模式: This is the regular world mode.
- 专家模式: Intended for experienced players, Expert mode worlds contain the same enemies, but with increased stats, and some have altered behavior patterns that make them more difficult to defeat. Loot drops are more frequent, however. As a special reward, bosses drop Treasure Bags which, in addition to the normal boss loot, also contain special items only available in Expert mode. Expert mode brings numerous other changes. See Expert Mode for a more complete list.
- 大师模式: A harder version of Expert mode, with no new AI but increased health and damage. It also includes 2 new drops per boss, and an extra accessory slot. See Master Mode for a more complete list.
- In an Expert Mode ( or Master Mode) world, enemies can steal the player's coins and despawn. On the 主机版和 移动版, this can be a tremendous setback as the enemies that steal the player's coins will not respawn with the coins, even if the player returns to the location where they died.
- In the 主机版和 移动版, Classic World mode is called "Normal Mode".
- In the 前代主机版, Classic Mode is called "Normal Mode" and Mediumcore is called "Difficult". Hardcore is still called "Hardcore".
- Hardcore mode can be utilized to freely explore a world by dying and flying through the ground and sky as a Ghost. However, Ghosts do not generate light, so exploring non-lit areas may be difficult.
- 电脑版 220.127.116.11：
- Journey mode option for world generation and character generation added. Journey characters can only play on Journey worlds and vice versa, and Journey Mode worlds have exclusive power features including item research and duplication, enemy difficulty control, infection spread control, and much more.
- Master mode, a harder version of Expert mode, added.
- Renamed Normal mode to Classic mode.
- Renamed Softcore to Classic.
- 电脑版 18.104.22.168：Fixed a crash when a Hardcore character died.
- 电脑版 22.214.171.124：现在中核/硬核模式下死亡时会正确掉落物品了。
- 电脑版 126.96.36.199：修正了硬核人物死亡后无法打开菜单的 Bug。
- 电脑版 188.8.131.52：中核人物现在死亡时会正确掉落弹药了。
- 电脑版 1.0.5：引入了硬核模式。
- Switch版 1.0.711.6：随电脑版 184.108.40.206 的更改引入。
- 移动版 220.127.116.11：引入中核和硬核难度，另外玩家现在可以选择难度了。