Have snowballs actually ever been able to hit players in vanilla?

Question

I've been trying to work out if thrown snowballs, in any vanilla version, have been able to hit, as in cause the damage animation and knockback (not necessarily actually taken away hearts, and not just disappearing on collision), other players in vanilla Minecraft? If so, in what version did this occur?

I've been searching about this for a while, but have only found conflicting claims:

• The IGN wiki claims "If an almost defeated enemy tries to tower up high into the sky to escape, you can simply throw snoballs [sic] at him until he falls down."
  • A few other PVP guides also claim that snowballs can be used to knock back players
• The Minecraft wiki makes no mention of snowballs affecting players, or ever having done so
  • Around the time snowballs were introduced, it even noted that snowballs do not affect players
• Many people seem to remember having snowball fights, even on unmodded servers.
  • For example, in this Reddit thread TheWyo claims it was a Bukkit plugin, and gets 26 downvotes
• Snowballs being unable to hit players is marked as a "bug" in the bug tracker, yet the mods too seem unsure whether this was ever actually a feature
  • A similar bug report was closed for being a "Feature request"
• There are Bukkit plugins which allow snowballs to damage players, which may be a cause of the confusion
• I personally checked the following versions in vanilla survival, and snowballs did no knockback or damage:
  • 1.8.3 full release (Latest version)
  • 1.2.5 full release
  • 1.0.0 full release
  • 1.8 beta
  • 1.4 beta
  • 1.0 beta
  • 1.2.1 alpha
  • 1.0.5 alpha (The first version in which snowballs existed)
• I cannot find anywhere/anyone that gives a version when this change was supposedly made.

In general, people seem very certain of remembering it, but are unable to provide evidence. If it is the case that snowballs once did knockback, it should be relatively easy to find or record a short clip showing so and post it; doing so is what I want for the answer to this question.

Is there any proof that snowballs knocking back players was actually ever a vanilla feature? If you believe this was once a vanilla feature give proof or a version number. I want an actual answer to this question, not just more of what people remember as I have listed above.

Answer 1

No. In vanilla Minecraft on a vanilla server, snowballs and other throwables do not hit players.

It's simply occam's razor; if snowballs didn't hit the player in alpha 1.0.5, and don't hit the player in release 1.8.4 (and also all versions after release 1.4.4, as confirmed in MC-3179), and there is no indication in any changelog that the behavior changed, let alone changed twice in between those versions, it stands to reason that such a change did not occur.

There are some server plug-ins that change this behavior, though. Snowball Damage is a Bukkit plugin that does precisely what it says on the tin. Similar plugins with similar functionalities exist. This is likely where the confusion comes. Many, many servers use Bukkit (in 2012, 80% of servers were running Bukkit. More current statistics are unavailable), so many users may have been exposed to such plugins, and are remembering behavior that does not exist in vanilla.

Answer 2

According to the decompiled source code of version 1.7.10 (the last version of the code you can get before Mojang began enforcing its will on not wanting the source code released), you can hit another player with a snowball, but it does no damage and causes no knockback.

The EntitySnowball class shows us that Snowballs only apply actual damage to Blazes (the damage value is 0, unless it's a Blaze, in which case its 3):

protected void a(MovingObjectPosition movingobjectposition) {
    if (movingobjectposition.entity != null) {
        byte b0 = 0;

        if (movingobjectposition.entity instanceof EntityBlaze) {
            b0 = 3;
        }

        movingobjectposition.entity.damageEntity(DamageSource.projectile(this, this.getShooter()), (float) b0);
    }
    //[...]
}

The damageEntity routine in the EntityLiving class does various things, like check invulnerability, calculate how much damage reduction a helmet has from falling anvils, checking fire resistance, and other things. Notably, it plays a hurt sound. This sound is played even if a damage value of 0 is given to the function. Also, notably, knockback isn't applied in the damageEntity() function; knockback is handled separately.

The final sticking point is the overridden damageEntity routine in the EntityPlayer class. Due to how overridding works, this method is called first when damaging a player. This method is written a little obtusely.

public boolean damageEntity(DamageSource damagesource, float f) {
    if (this.isInvulnerable()) {
        return false;
    } else {

Obviously, if the player is invulnerable for whatever reason, no damage is applied (and no sound is produced).

        boolean flag = this.server.X() && this.server.getPvP() && "fall".equals(damagesource.translationIndex);

        if (!flag && this.invulnerableTicks > 0 && damagesource != DamageSource.OUT_OF_WORLD) {
            return false;

This extremely confusing set of checks is finding instances when damage wouldn't be applied. Considering that Minecraft actually functions, chances are this "return false" is often passed over successfully.

        } else {
            if (damagesource instanceof EntityDamageSource) {
                Entity entity = damagesource.getEntity();

                if (entity instanceof EntityHuman && !this.a((EntityHuman) entity)) {
                    return false;
                }

This line checks to see if the damage is coming from a Human. The this.a() function checks the server's PvP setting, and then if the other player is a team ally. If the PvP is off, or the other player is an ally, the function returns here and no damage is done nor hurt sound produced. Note, this line checks for the one player punching another (possibly with weapon in hand) and not for projectiles.

                if (entity instanceof EntityArrow) {
                    EntityArrow entityarrow = (EntityArrow) entity;

                    if (entityarrow.shooter instanceof EntityHuman && !this.a((EntityHuman) entityarrow.shooter)) {
                        return false;
                    }
                }

These lines, however, check for projectiles. Or rather, for Arrows, only. As it only checks for only Arrows, other projectiles like Snowballs and Eggs are not included in this check. Thus when throwing a snowball, these lines are not executed.

            }

            return super.damageEntity(damagesource, f);
        }
    }
}

Finally, the function ends by calling the method described above in the EntityLiving class, which applies damage and produces a "hurt" sound. Note that because the Snowball bypasses the Arrow in PvP check, it should "hit" the other player, in that the other player will make a sound and apply invulnerability flashing. However, snowballs do no damage and produce no knockback.

(By extension, Eggs should work the exact same way, as they too pass a 0 to the damageEntity() function).

Answer 3

Chances are, whether a snowball will hit another player or not is entirely dependant on if PvP is enabled. Because, after all, if a snowball does indeed hurt someone and cause knockback, then you wouldn't want that affecting other players on non-PvP servers.

Answer 4

Yes, throwing a snowball is like throwing an egg. It will hit you, make the sound and animation, and it might even do damage. Snowballs do very little damage, if any, but they do actually hit another player. You could also hit yourself by throwing it straight up in the air and letting it fall onto you