/scoreboard objectives add armor dummy

Adds a score called armor that can only be changed with commands

/scoreboard players set @a armor 0

Sets the score at 0, this is used to super-fast reset the score

/scoreboard players set @a armor n {Inventory:[{Slot:xb,id:"minecraft:id"}]}

Sets at "n" the score of all the players with "id" in their "x" slot

Helmet slot: 103b
Chestplate slot: 102b
Leggings slot: 101b
Boots slot: 100b

/clear @a[score_armor_min=n,score_armor=n] id

Removes "id" from the inventory of all the players with the score setted at "n"

Difficulty: EASY (2/5)
Commands in the mechanic: NORMAL (6)
External commands: LOW (1)

/scoreboard objectives add item dummy

Adds a score called "item", that can only be changed with commands

/scoreboard players set @a item 0

Sets at 0 the score of all players: this is the base of the "auto-resetting" mechanism

/scoreboard players set @a item n {Inventory:[{id:"minecraft:id"}]}

Sets the at "n" the score of all the players with an item ("id") in the inventory

/scoreboard players set @a item n {Inventory:[{Slot:xb,id:"minecraft:id"}]}

Sets the at "n" the score of all the players with an item ("id") in their "x" slot

/scoreboard players set @a item n {SelectedItem:{id:"minecraft:id"}}

Sets the at "n" the score of all the players that are selecting an item ("id")

summon FallingSand ~ ~1 ~ {Block:stone,Time:1,Passengers:[{id:FallingSand,Block:redstone_block,Time:1,Passengers:[{id:FallingSand,Block:activator_rail,Time:1,Passengers:[{id:MinecartCommandBlock,Command:gamerule commandBlockOutput false},{id:MinecartCommandBlock,Command:"fill ~2 ~-3 ~-2 ~6 ~1 ~2 obsidian 0 hollow"},{id:MinecartCommandBlock,Command:"fill ~2 ~-2 ~-2 ~6 ~ ~2 stained_glass 1 replace obsidian"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"----------------------------------------------------\",\"color\":\"gold\"}]"},{id:MinecartCommandBlock,Command:setblock ~1 ~-3 ~-1 wall_sign 4 replace {Text1:"{\\\"text\\\":\\\"deactivate\\\",\\\"color\\\":\\\"dark_red\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/blockdata ~2 ~1 ~ {auto:0b}\\\"}}",Text2:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/playsound minecraft:block.chest.close voice @a ~ ~ ~ 10 1 1\\\"}}",Text3:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/fill ~1 ~1 ~-1 ~9 ~3 ~4 stained_glass 14 replace stained_glass\\\"}}",Text4:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}"}},{id:MinecartCommandBlock,Command:setblock ~1 ~-3 ~1 wall_sign 4 replace {Text1:"{\\\"text\\\":\\\"activate\\\",\\\"color\\\":\\\"green\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/blockdata ~2 ~1 ~-2 {auto:1b}\\\"}}",Text2:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/playsound minecraft:block.chest.open voice @a ~ ~ ~ 10 1 1\\\"}}",Text3:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/fill ~1 ~1 ~-3 ~9 ~3 ~4 stained_glass 1 replace stained_glass\\\"}}",Text4:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}"}},{id:MinecartCommandBlock,Command:setblock ~1 ~1 ~ wall_sign 4 replace {Text1:"{\\\"text\\\":\\\"destroy\\\",\\\"color\\\":\\\"red\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/setblock ~2 ~-1 ~ redstone_block 0\\\"}}",Text2:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/playsound entity.generic.explode voice @a ~ ~ ~ 12 2 1\\\"}}",Text3:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}",Text4:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}"}},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"Zombie-Ghost in vanilla minecraft v 1.0 by GYGY. Click on the explenation sign to get started.\",\"color\":\"aqua\"}]"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"----------------------------------------------------\",\"color\":\"gold\"}]"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"Don't spam this command as your own one, and if you are a youtuber credit me and leave a link to my channel.\",\"color\":\"aqua\"}]"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"----------------------------------------------------\",\"color\":\"gold\"}]"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"Remember also to take a look of my channel:\",\"color\":\"aqua\"},{\"text\":\" My channel\",\"color\":\"dark_aqua\",\"clickEvent\":{\"action\":\"open_url\",\"value\":\"https://www.youtube.com/channel/UC3_Gm-pfskCh2bnzcekR0ow\"}}]"},{id:MinecartCommandBlock,Command:"/tellraw @a [\"\",{\"text\":\"----------------------------------------------------\",\"color\":\"gold\"}]"},{id:MinecartCommandBlock,Command:setblock ~1 ~-1 ~ wall_sign 4 replace {Text1:"{\\\"text\\\":\\\"\\\",\\\"color\\\":\\\"dark_blue\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/tellraw @a [\\\\\\\"\\\\\\\",{\\\\\\\"text\\\\\\\":\\\\\\\"This command adds a new mob: the Zombie-Ghost: its spawning chance is of the 10% every 100 game ticks. It is invisible and really powerful: you can't shot it by normal arrows, and it gives hunger and mining fatigue effects. To see it you have to put a pumpkin on your head. Sometimes it drops a ghost tear: if you put it in your left hand you'll be able to see all the ghosts, but if you get nearby it with a ghost thear it will steal it to you, and he'll summon another Zombie-ghost. Also remember to take a look of my channel: \\\\\\\",\\\\\\\"color\\\\\\\":\\\\\\\"gold\\\\\\\"},{\\\\\\\"text\\\\\\\":\\\\\\\"My channel\\\\\\\",\\\\\\\"color\\\\\\\":\\\\\\\"dark_aqua\\\\\\\",\\\\\\\"clickEvent\\\\\\\":{\\\\\\\"action\\\\\\\":\\\\\\\"open_url\\\\\\\",\\\\\\\"value\\\\\\\":\\\\\\\"https://www.youtube.com/channel/UC3_Gm-pfskCh2bnzcekR0ow\\\\\\\"}}]\\\"}}",Text2:"{\\\"text\\\":\\\"Explenation\\\",\\\"color\\\":\\\"dark_blue\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/execute @a ~ ~ ~ playsound minecraft:entity.experience_orb.pickup voice @a ~ ~ ~ 12 1 1\\\"}}",Text3:"{\\\"text\\\":\\\"\\\",\\\"color\\\":\\\"dark_blue\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"2\\\"}}",Text4:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"3\\\"}}"}},{id:MinecartCommandBlock,Command:setblock ~7 ~-1 ~ wall_sign 5 replace {Text1:"{\\\"text\\\":\\\"Change\\\",\\\"color\\\":\\\"gold\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"/fill ~-1 ~2 ~2 ~-5 ~-2 ~-2 stained_hardened_clay 15 replace obsidian\\\"}}",Text2:"{\\\"text\\\":\\\"machine's\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}",Text3:"{\\\"text\\\":\\\"style\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}",Text4:"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"\\\"}}"}},{id:MinecartCommandBlock,Command:scoreboard objectives add zght dummy},{id:MinecartCommandBlock,Command:scoreboard objectives add zghc dummy},{id:MinecartCommandBlock,Command:setblock ~3 ~-2 ~-1 repeating_command_block 5 replace {auto:1b,Command:"/execute @a ~ ~ ~ scoreboard players add @e[type=Zombie,r=20] zght 1"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-2 ~-1 chain_command_block 5 replace {auto:1b,Command:"/scoreboard players add @a zght 1"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-2 ~-1 chain_command_block 3 replace {auto:1b,Command:"/scoreboard players set @a[score_zght_min=31] zght 0"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-2 ~ chain_command_block 4 replace {auto:1b,Command:"/execute @a[score_zght_min=30] ~ ~ ~ entitydata @r[type=Zombie,score_zght=10] {CustomName:\\\"Ghost\\\",CustomNameVisible:0b}"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-2 ~ chain_command_block 4 replace {auto:1b,Command:"/execute @a[score_zghc=0] ~ ~ ~ effect @e[type=Zombie,name=Ghost] 14 1 255 true"}},{id:MinecartCommandBlock,Command:setblock ~3 ~-2 ~ chain_command_block 3 replace {auto:1b,Command:"/entitydata @e[type=Zombie,name=Ghost] {Fire:-1s,PersistenceRequired:1,ArmorItems:[{Count:1,id:ghast_tear,tag:{display:{Name:\\\"Ghost tear\\\",Lore:[\\\"From GYGY's Ghost-Zombie Vanilla ModPack\\\"]}}},{Count:1,id:redstone},{Count:1,id:spectral_arrow},{}],ArmorDropChances:[0.4F,0.5F,0.7F,0.0F],ZombieType:6}"}},{id:MinecartCommandBlock,Command:setblock ~3 ~-2 ~1 chain_command_block 5 replace {auto:1b,Command:"/scoreboard players set @a zghc 0"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-2 ~1 chain_command_block 5 replace {auto:1b,Command:"/scoreboard players set @a zghc 1 {Inventory:[{Slot:103b,id:\\\"minecraft:pumpkin\\\"}]}"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-2 ~1 chain_command_block 1 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ effect @e[type=!Zombie,r=5] 17 3 5 true"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-1 ~1 chain_command_block 4 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ execute @e[type=!Zombie,r=5] ~ ~ ~ effect @e[type=Zombie,name=Ghost] 11 1 3 true"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-1 ~1 chain_command_block 4 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ effect @e[type=!Zombie,r=5] 4 3 5 true"}},{id:MinecartCommandBlock,Command:setblock ~3 ~-1 ~1 chain_command_block 2 replace {auto:1b,Command:"/effect @e[type=Zombie,name=Ghost] 1 1 5 true"}},{id:MinecartCommandBlock,Command:setblock ~3 ~-1 ~ chain_command_block 5 replace {auto:1b,Command:"/execute @a ~ ~ ~ execute @e[type=Zombie,name=Ghost,rm=6] ~ ~ ~ tp @e[type=Arrow,r=5] ~ ~ ~ ~10 ~"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-1 ~ chain_command_block 5 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ entitydata @e[type=Arrow,r=5] {NoGravity:1b,Motion:[0.0,0.0,0.0]}"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-1 ~ chain_command_block 2 replace {auto:1b,Command:"/scoreboard players set @a zghc 2 {Inventory:[{Slot:-106b,id:\\\"minecraft:ghast_tear\\\",tag:{display:{Name:\\\"Ghost tear\\\"}}}]}"}},{id:MinecartCommandBlock,Command:setblock ~5 ~-1 ~-1 chain_command_block 4 replace {auto:1b,Command:"/execute @a[score_zghc=0] ~ ~ ~ effect @e[type=Zombie,name=Ghost] 24 0 0"}},{id:MinecartCommandBlock,Command:setblock ~4 ~-1 ~-1 chain_command_block 4 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ entitydata @e[type=SpectralArrow,r=5] {NoGravity:1b}"}},{id:MinecartCommandBlock,Command:setblock ~3 ~-1 ~-1 chain_command_block 1 replace {auto:1b,Command:"Nothing here"}},{id:MinecartCommandBlock,Command:setblock ~3 ~ ~-1 chain_command_block 5 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ clear @a[r=5] ghast_tear 0 1 {display:{Name:\\\"Ghost tear\\\"}}"}},{id:MinecartCommandBlock,Command:setblock ~4 ~ ~-1 chain_command_block 13 replace {auto:1b,Command:"/execute @e[type=Zombie,name=Ghost] ~ ~ ~ entitydata @r[type=Zombie,rm=1,r=20] {CustomName:\\\"Ghost\\\"}"}},{id:MinecartCommandBlock,Command:setblock ~ ~ ~1 command_block 0 replace {Command:fill ~ ~-3 ~-1 ~ ~ ~ air}},{id:MinecartCommandBlock,Command:setblock ~5 ~ ~-1 chain_command_block 5 replace {auto:1b,Command:"/execute @a[score_zghc_min=1] ~ ~ ~ effect @e[type=Zombie,name=Ghost,rm=6] 24 1 255 true"}},{id:MinecartCommandBlock,Command:setblock ~4 ~ ~ command_block 5 replace {auto:0b,Command:"/scoreboard objectives remove zghc"}},{id:MinecartCommandBlock,Command:setblock ~5 ~ ~ chain_command_block 3 replace {auto:1b,Command:"/scoreboard objectives remove zght"}},{id:MinecartCommandBlock,Command:setblock ~5 ~ ~1 chain_command_block 4 replace {auto:1b,Command:"/fill ~-4 ~-3 ~-3 ~2 ~1 ~1 air 0"}},{id:MinecartCommandBlock,Command:setblock ~ ~-1 ~1 redstone_block},{id:MinecartCommandBlock,Command:kill @e[type=MinecartCommandBlock,r=1]}]}]}]}

Difficulty: REALLY EASY (1/5)
Commands in the mechanic: LOW (2)
External commands: LOW (1)

/scoreboard objectives add explosion dummy

Adds a score called "explosion" which can be changed only using commands

/execute @a ~ ~ ~ scoreboard players set @e[type=PrimedTnt,rm=2] explosion 1 {Fuse:2s}

Makes all the players set at 1 the score of all the Tnts in the range of two blocks or more [rm=2], but only when their fuse is at 2

/execute @a ~ ~ ~ entitydata @e[type=PrimedTnt,score_explosion_min=1,rm=2] {Fuse:10s}

Makes all the player set the fuse of all the Tnts (in the range of two blocks or more [rm=2] and with the score at 1 or more) at 10

Difficulty: MEDIUM (3/5)
Commands in the mechanic: MEDIUM (7)
External commands: NORMAL (3)

/scoreboard objectives add block dummy

Adds a score called "block": it can be changed only using commands

/summon Chicken ~ ~1 ~ {Silent:1b,CustomName:"block",Invisible:1b,Passengers:[{id:Zombie,IsBaby:1b,CustomName:"block",Silent:1b},{id:FallingSand,Time:1b,TileID:87,CustomName:"block"},{id:Shulker,NoAI:1b,Silent:1b,CustomName:"block"}]}

Summons a chicken with a zombie, a falling sand with custom id (basically every block/item has a numeric id, and you can know it by pressing f3+h [windows] or fn+f3+h [mac/linux]: to summon a different block just replace the "87" with the number of the block you want) and a shulker on it

/summon Chicken ~ ~1 ~ {Silent:1b,CustomName:"block",Invisible:1b,Passengers:[{id:Creeper,CustomName:"block",Silent:1b},{id:FallingSand,Time:1b,TileID:46,CustomName:"block"},{id:Shulker,NoAI:1b,Silent:1b,CustomName:"block"}]}

The same of the first, but with a creeper on the chicken

/effect @e[type=!Player,name=block] 14 1 1 true

Gives invisibility effect to all the entities that aren't players and are called "block"

/entitydata @e[type=FallingSand,name=block] {Time:1b}

Changes sand's despawn time, so it doesn't despawn

/scoreboard players set @e[type=!Chicken,name=block] block 1 {OnGround:1b}

Sets at 1 the score of all the entities that aren't chickens, only if they are on the ground and are called "block"

/kill @e[type=!Player,score_block_min=1]

Kills all the entyties that have the score at 1 and aren't players

/scoreboard players set @a block 0

Resets the score of all the players

/execute @a ~ ~ ~ execute @e[type=Chicken,name=block,r=5] ~ ~ ~ scoreboard players add @a[r=5] block 1

Sets at 1 the score of a player in the range of 5 blocks nearby a zombie

/execute @a[score_block=0] ~ ~ ~ kill @e[type=Shulker,name=block,r=5]

If a player has the score at 0 (the chicken have been killed), the shucker will be killed