Third Life is a game mode created by Grian. Every player gets three lives.

your name will appear a different colour depending on how many lives you have.

Green = 3 lives

Yellow = 2 Lives

Red = 1 Life

Once a player has a red life, their alliances are broken and they can start killing. Your objective is to be the last one standing.

To start type /reload

Crafting:

Helmets are un-craftable
The enchantment table is un-craftable
Bookshelves are un-craftable
Added a more straightforward crafting recipe for TNT.
Saddles and horse armour are now craftable

What is the difference between this mod pack and the game? To be brief, more content.

Bloodmoon:

A crimson moon will appear in the sky every so often making your chance for survival thin. As the sky bleeds red, all rules that apply to a red name now apply to all.

Lucky Blocks:

Yes, Lucky Blocks. Why? To gamble your life. You can get good loot or a disaster that will take you out of the game. So, it is up to you if you want to break one.

Shrinking World Boarder:

The border will shrink in 5 minutes once you type in the start command. Each player will be notified how much time they have left every so often.

Commands:

"/function shrinkingborder:start"

"/scoreboard players set PLAYER deaths 0" Changes the number of lives a player has.

Credit:
Third Life datapack