Server

Mods
Rules

More commands available onMinecraft Wiki.

Command Blocks

/gamerule commandBlocksEnabled true# Default: false

Keep Inventory

Must be run in every dimension.

/gamerule keepInventory true# Default: false

Entity Cramming

/gamerule maxEntityCramming 42# Default: 24

"The old man sat outside, whiskey in hand. Thoughts drifting to memories. That time, those stories, that other time, those other stories. He smiles. Memories of when whiskey wasn't trendy. Memories of a time when memories were only told through memories. His smile widens. Ah yes, memories of memories." -FrankB13