Minecraft – Generate a command block with variable data

In the source there are couple functions that attempt to obtain a target: one that selects players first (and if it fails, falls back to the other function), and one that does not have a bias towards any type. Every command must choose which one to use when it has a selector.

However, player bias will only occur if the selector itself is @p or @r (without c being changed) or the c parameter is set to value of exactly "1". If so, the selector won't be processed yet and the command class itself will use one of those functions to process it. Otherwise, the selector is processed first with no bias and then the command is processed for each target found, being handed the already-obtained target (and not a selector to process).

Almost all /scoreboard commands use the player bias function, except for /scoreboard players tag ... and /scoreboard teams join .... The stored selector for CommandStats also uses it.

The only way to prevent it from targeting players is to exclude players from selection:

/execute @e[type=ArmorStand] ~ ~ ~ detect ~ ~-1 ~ stone 0 scoreboard players set @e[type=!Player,c=1] myObj 1

This does mean that if you want a nested /scoreboard command or CommandStats to still target all entities including players, you'd have to create two copies: one for players and one for non-player entities:

/execute @e[type=!Player] ~ ~ ~ /scoreboard players set @e[type=!Player,c=1] OBJ 1
/execute @a ~ ~ ~ /scoreboard players set @a[c=1] OBJ 1

Or:

/stats entity @e[type=!Player] set SuccessCount @e[type=!Player,c=1] OBJ
/stats entity @a set SuccessCount @a[c=1] OBJ

No, unfortunately there is nothing really quite like "variables" in Minecraft. However, there is the scoreboard, which you can use for certain things. If there's something specific you'd like to do, try asking that as well; you'll be surprised by the number of ways people have gotten around the absence of variables.

Here's a quick walk through of what you can do with the scoreboard:

/scoreboard objectives add name dummy - Adds objective name

/scoreboard players set|add|subtract entity objective value NBT Tag - Modifies objective score of entity, if entity's NBT data matches NBT Tag. NBT tag is optional.

/scoreboard players reset entity objective - Resets objective score if entity. Leave objective blank to reset all scores for this entity

Now for target selector arguments:

score_objective=value - Entities with a maximum objective score of value

score_objective_min=value - Entities with a minimum objective score of value

Hope this helped! Make sure to check out the Minecraft Wiki when in doubt. Here's a link to page on Scoreboards: Scoreboard - Official Minecraft Wiki