Terraria separates identity from environment: player characters live in .plr files and worlds live in .wld files. That makes a complete backup a two-part job. Copy both directories, including .bak companions, before editing or moving systems. Steam can independently move individual characters and worlds to cloud storage, so an apparently missing local file may have a counterpart under Steam userdata. SaveEditor.com keeps those locations distinct instead of presenting one universal Terraria save path.
Choose the correct backup boundary
For Terraria, the researched PC save location is Windows: %USERPROFILE%DocumentsMy GamesTerraria
Steam cloud copies may appear under <Steam-folder>userdata<user-id>105600remoteplayers and worlds | macOS: $HOME/Library/Application Support/Terraria/ | Linux / Steam Play: $XDG_DATA_HOME/Terraria/ (normally ~/.local/share/Terraria/). The known save file or folder pattern is Players*.plr
Worlds*.wld
*.bak. Back up both Players and Worlds plus their .bak files. If a character and world belong together, keep them in the same dated archive even though they are separate files. Copying the complete documented save boundary is safer than selecting one visually obvious file, because companion metadata, indexes, backups, or multiple slots can be required together.
Make an offline copy before changing anything
Close the game first, wait for the active launcher to finish writing, then copy the save data to a separate folder that the game and sync client do not watch. Label the copy with the game, storefront, profile, and date. Documented launcher context: Steam, GOG Galaxy. Steam can keep cloud-designated player/world files under its userdata remote tree. The normal local Terraria directory still separates Players and Worlds.
Account for cloud saves
Steam Cloud and GOG Galaxy are documented. On Steam, cloud movement is enabled per character/world rather than being assumed for every local file. Before restoring an older backup, decide which copy should win. If the game or launcher starts while an older manual copy is in place, synchronization can replace it before you confirm that it works. Keep the untouched backup outside the live save path until the restored progress has been opened and saved normally.
Restore without changing format assumptions
Characters and worlds are separate files: .plr for players and .wld for worlds. Local .bak companions can provide rollback material. Multiplayer characters and worlds should therefore be backed up as separate sets. Compatibility note: A world file and a player file have different structures and cannot replace one another. Cloud status can also differ per file. Restore into the matching storefront/profile context whenever possible. Do not rename a save extension, move a folder into a different container type, or assume a console/mobile copy is equivalent unless a tested migration path specifically says so.
Recovery fallback
If a character or world is missing, check both the local directory and Steam remote location. Before using a .bak copy, preserve the current .plr/.wld and the backup so the recovery remains reversible. If the restored copy fails, put the untouched original back first. Then compare location, account/profile, cloud state, and the full directory structure before trying a different backup. The objective is reversible recovery, not repeated destructive experiments on the only copy.
Verification context: Windows/macOS/Linux locations, .plr/.wld patterns, Steam remote paths, and per-item Steam cloud behavior were reviewed against current PCGamingWiki coverage.