Minecraft – Can you use /testfor to detect the death of a player

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Can you use the /testfor command in minecraft 1.8 to find out if a player has died ?

I need it for my map, where 2 players (Only) are pitted against eachother. I want it so that when one of them dies, it will detect the death and declare the victor.

Best Answer

The usual way to test for dead players is to set up a scoreboard objective. Check out the linked wiki page for general information, as well as the command reference for using scoreboards.

First, you have to set up an objective, I'll call it hasDied using

/scoreboard objectives add hasDied deathCount

Using the deathCount criterion means that it is automatically updated when someone dies. Now you can check whether a player has died using

/testfor @a[score_hasDied_min=1]

On a clock. The output of this command block will turn on once at least one player, somewhere, has a death score of at least 1. As part of this output (or the game start routine) you should reset the scoreboard objective for everyone using

/scoreboard players set @a hasDied 0

For an unknown number of players detecting the last man standing can be tricky, but it's doable. You can easily track people that have not died (using @a[score_hasDied=0]), and detect when the comparator outputs at signal strength 1.

Related Solutions

Minecraft – use command blocks to teleport a player who died

Any selector arguments you use in testfor can be used in tp. Like so:

1.7 to 1.12: /tp @a[score_HEALTH=1] X Y Z
1.13+:       /tp @a[scores={HEALTH=..1}] X Y Z

There are problems with using low health to check for death. Instead, I'd recommend adding a deaths scoreboard:

/scoreboard objectives add deaths deathCount

This score will get set to 1 when a player dies (automatic, because of the type of objective), your commands can teleport players with a deaths score of 1 and then set it back to 0 (so the player isn't repeatedly teleported).

The following commands are a full solution, including the team score incrementing, for 1.13+:

tp @a[scores={deaths=1..}] 73 10 31
execute as @a[scores={deaths=1..},team=red] run scoreboard players add blue points 1
execute as @a[scores={deaths=1..},team=blue] run scoreboard players add red points 1
scoreboard players set @a deaths 0

Minecraft – Using /testfor in minecraft to check if a player has a certain item in their inventory

It's very difficult to see whether someone has an object anywhere in their inventory. That would take 36 command blocks, one for each slot! You can, however, take the object, then see if taking the object worked.

The Commands

Set up a fast clock (but not as fast as a fill clock)
One command block does /clear @p iron_ingot 0 1 (clears 1 iron ingot from the nearest player. You can choose which player, but it must be exactly one. Also, you must use the same selector throughout all these commands.)
Run a comparator from that command block to another command block running this command: /scoreboard players add @p ironIngots 1 (Increases the player's ironIngots score by 1. Make sure you create ironIngots first!)
Create another command block that does whatever you want. In the case of giving them a diamond, you would do this: /give @p[score_ironIngots_min=10] diamond. Note the target selector; it gives the player the diamond only if their ironIngots score is 10 or greater.
The last thing you want to do is take the ironIngots score away so they don't keep getting items. Just run /scoreboard players remove @p[score_ironIngots_min=10] ironIngots 10. This removes 10 iron ingots from the player if they have an ironIngots score of 10 or greater. Any player who matches this will have received a diamond in the previous step.

How to Set Them Up

The commands listed above must run in order. It is actually very simple to put them in order. Just open the debug menu and look at the stylish new crosshair. Align the command blocks along either the green or red line so that one of those lines points down the first to the last command block.

Notes

You don't have to press a button to use this, you just have to be the nearest player. You can change the command to the nearest player within 10 blocks, nearest player on a team, etc.
The commands will take a short amount of time to finish, but for 10 iron ingots, it will only take half a second. It's one tick (1/20 of a second) per item taken away.
It will take away iron ingots even if you don't have ten. However, you can submit one, then later submit five, then submit four more later, and it will still give you the diamond. You can also submit 14 at a time and the extra 4 will be saved for later.