NoBadBooms!

A server-side NeoForge 1.21.1 mod that adds a tntExplodes gamerule, similar to Bedrock Edition, letting you stop TNT from destroying blocks.

Usage

/gamerule tntExplodes false

When false, TNT blocks and TNT minecarts still ignite and detonate (fuse, sound, particles, knockback, and entity damage all still happen), but no blocks are destroyed. Default is true (vanilla behavior).

The rule is per-world and saved like any vanilla gamerule.

Note: this differs slightly from Bedrock, where tntExplodes false prevents TNT from igniting at all. Here the explosion still occurs - only terrain damage is disabled. Other explosion sources (creepers, ghasts, beds, end crystals) are unaffected; creepers are already covered by vanilla's mobGriefing.

Server-side only

Install the jar in the server's mods folder. Vanilla / unmodded clients can join normally. It also works in single-player if installed on a client.

How it works

• Registers the gamerule with GameRules.register("tntExplodes", Category.MISC, BooleanValue.create(true)) during mod class initialization (NeoForge's access transformers make these public).
• Listens to ExplosionEvent.Detonate, which fires after the explosion has computed its affected blocks but before anything is destroyed. If the explosion's direct source entity is a PrimedTnt or MinecartTNT and the gamerule is false, the affected-block list is cleared.

Note: This was to solve an issue with a minigame on my server. I don't know if I will ever update it. I don't imagine it will be hard to update, so, feel free to compile from source and change however you want. It's a tool, use it if you need.