Changing your server's gamemode

Within Minecraft, there are 5 available gamemodes; Survival, Creative, Adventure, Spectator and Hardcore.

Changing the server's gamemode

Firstly head to the Configure section of NodePanel, followed by the Gamemode Settings tab.
Next, choose your preferred gamemode using the dropdown menu at the top of the page. If you're wanting hardcore, select Survival, and then following step 3 below.
For hardcore, ensure that the Hardcore box is checked.
Restart your server.

If you change the gamemode after players have already joined, they may be locked in the old gamemode. You can use the Force Gamemode option to ensure these players are forcefully set to the newly set gamemode after the server restarts.

Gamemode Types

Survival

In this mode, players have to gather all their materials to build, craft and gain experience points. Dying will send the player back to their spawn point, which is set at their bed, or the first location they enter the server.

Creative

The player has access to an infinite amount of almost all blocks and items available, and can destroy them instantly. Players are invulnerable and do not have health, armor, or hunger, and can fly. The player has access to items not available in Survival mode, e.g. spawn eggs.

Adventure

Players can interact with objects such as levers and buttons, and can interact with mobs. However, they can only break/place specific blocks as configured by a map creator or developer. This mode is best suited for adventure maps.

Hardcore

In this mode, which plays in the same way as Survival mode, the difficulty level is permanently set to "Hard", and when the player dies, the only choice is that the map must be deleted, or the player is sent permanently into spectator mode. On a server, if someone dies, they will be banned. If everyone on a server gets banned, the world for the server will be deleted.

Hardcore mode is technically a modifier rather than a gamemode, but is different enough to be generally considered its own mode.

Spectator

This gamemode was implemented in version 1.8 of Minecraft. When in spectator mode, you can clip through blocks (noclip), see what other entities are seeing by left-clicking on them, and you're invisible to everything and everyone except for other spectators. You can't interact with blocks, entities or your inventory.