[MC-120083] Players still earn advancements in spectator mode

The Bug

A player can still earn advancements in spectator mode, and they are still broadcast to the server. You can test this by going into spectator mode, and /giving yourself an elytra.

Steps to Reproduce

Revoke all advancements from yourself.
```
/advancement revoke @s everything
```
Switch into spectator mode and give yourself a lava bucket.
```
/give @s minecraft:lava_bucket
```
Take note as to whether or not you are granted the "Hot Stuff" advancement.

Observed Behavior

Players are able to earn advancements whilst in spectator mode.

Expected Behavior

Players would not be able to earn advancements whilst in spectator mode.

Code analysis

Code analysis by @unknown can be found on this comment.

Linked issues

is duplicated by 1

MC-278726 "Minecraft: Trial Edition" advancement can be achieved in spectator mode Resolved

Attachments

Comments 32

[Mod] bemoty 2017-08-12T14:28:00Z

Can confirm for MC 1.12.1.

tryashtar 2017-08-12T16:45:32Z

I've reproduced inventory advancements (e.g. get a lava bucket) and location advancements (e.g. find a nether fortress). I could not reproduce "enter block" advancements (e.g. enter an end gateway). Starting to breed animals then entering spectator mode also provides the advancement.

Recipes are also unlocked when their advancement is triggered.

[Mod] bemoty 2017-08-12T18:14:13Z

I could not reproduce "enter block" advancements (e.g. enter an end gateway).

@unknown check MC-46421.

tryashtar 2017-08-13T19:18:14Z

Alright, just now I did a more thorough check to see which advancement triggers can be activated by players in spectator mode. I did this by creating an advancement with one criteria, a single trigger of each name with no additional conditions (unless they were required (recipe_unlocked)). The results:
Can be triggered by spectators:

bred_animals (breed, then switch gamemodes)
changed_dimension (by teleporting across)
cured_zombie_villager (feed, then switch gamemodes)
effects_changed
entity_hurt_player (via /kill)
inventory_changed
levitation
location
player_hurt_entity (ignite TNT, then switch gamemodes)
player_killed_entity
recipe_unlocked
nether_travel (enter portal, switch gamemodes, teleport across)
summoned_entity (ender dragon)
tick

Cannot be triggered by spectators, either because the action is impossible (such as taming an animal) or it simply doesn't trigger (such as entering a block):

brewed_potion
construct_beacon
consume_item
enchanted_item
enter_block
entity_killed_player
impossible 😉
item_durability_changed
placed_block
slept_in_bed
tame_animal
used_ender_eye
used_totem
villager_trade

Kyiiel 2017-08-19T16:02:50Z

Might want to put that this issue relates to MC-46421, because if that is fixed, then it will be affected by this bug.

22 more comments

lord.quadrato 2018-05-31T20:38:24Z

Confirmed for 18w22c

lord.quadrato 2018-06-04T20:19:04Z

Confirmed for 1.13-pre1

lord.quadrato 2018-06-16T20:47:01Z

Confirmed for 1.13-pre2

Egor Hans 2018-06-17T15:56:38Z

I'd have expected this to be WAI. For all other game modes, the following rule applies: If you fulfill the conditions for an achievement/advancement, you get it, no matter whether you normally should be able to fulfill the condition. And I don't see why Spectator Mode should be an exception, since it will never affect other players. I assume this will end up marked as WAI.

lord.quadrato 2018-06-21T20:03:40Z

Confirmed for 1.13-pre3

I see you problem, @Egor Hans, but when you are specator you can for example fly around to find a fortress or stay around a beacon being activated from another player and you would gain the achievement. When you are switched back to survival then you have claimed advancements without actually doing the required thing in survival play. So this bug can be used to gain an advantage over other players

lord.quadrato 2018-06-27T16:55:58Z

Confirmed for 1.13-pre4

wobst.michael 2020-05-03T06:33:33Z

Can this still be reproduced in the latest 1.16 snapshot?

DrownedZombie 2020-05-03T08:43:05Z

Can still be reproduced in the latest snapshot. Whenever I go near a fortress in spectator mode, the "A Terrible Fortress" advancement toast is announced.

timeflow x 2020-06-04T10:28:19Z

this is still an issue in 20w22a, where I got the hot tourist destinations advancement in spectator mode

pulpetti 2020-07-18T14:46:42Z

Still in 1.16.1 and 20w29a.

Avoma 2020-11-30T19:10:19Z

Can confirm in 20w48a.

Avoma 2021-01-29T12:54:58Z

Can confirm in 21w03a.

Avoma 2021-02-08T09:01:08Z

Can confirm in 21w05b.

Avoma 2021-02-15T09:20:36Z

Can confirm in 21w06a.

JochCool 2021-05-27T15:51:11Z

Affects 1.17-pre1, and also affects new advancements like Surge Protector.

ampolive 2021-07-02T20:44:11Z

Can confirm in 1.17.1 Release Candidate 1.

JochCool 2021-09-16T14:07:50Z

Affects 21w37a.

ampolive 2021-10-06T20:19:19Z

Can confirm in 21w39a.

Avoma 2021-10-14T12:03:15Z

I am able to confirm this behavior in 21w41a. Here are some extra details regarding this problem.

The Bug:

Players are able to earn advancements whilst in spectator mode.

Steps to Reproduce:

Revoke all advancements from yourself.

/advancement revoke @s everything

Switch into spectator mode and give yourself a lava bucket.

/give @s minecraft:lava_bucket

Take note as to whether or not you are granted the "Hot Stuff" advancement.

Observed Behavior:

Players are able to earn advancements whilst in spectator mode.

Expected Behavior:

Players would not be able to earn advancements whilst in spectator mode.

ampolive 2021-10-21T22:34:55Z

Can confirm in 21w42a.

Avoma 2021-12-13T19:06:15Z

Can confirm in 1.18.1.

Avoma 2022-01-10T14:57:03Z

Here's a code analysis of this issue. The following is based on a decompiled version of Minecraft 1.18.1 using MCP-Reborn. Please note that I'm quite tentative about this analysis, although I'm persuaded to believe that this is likely the cause of the problem. 🙂

Code Analysis (tentative):

net.minecraft.server.PlayerAdvancements.java

public class PlayerAdvancements {
   ...
   public boolean award(Advancement p_135989_, String p_135990_) {
      boolean flag = false;
      AdvancementProgress advancementprogress = this.getOrStartProgress(p_135989_);
      boolean flag1 = advancementprogress.isDone();
      if (advancementprogress.grantProgress(p_135990_)) {
         this.unregisterListeners(p_135989_);
         this.progressChanged.add(p_135989_);
         flag = true;
         if (!flag1 && advancementprogress.isDone()) {
            p_135989_.getRewards().grant(this.player);
            if (p_135989_.getDisplay() != null && p_135989_.getDisplay().shouldAnnounceChat() && this.player.level.getGameRules().getBoolean(GameRules.RULE_ANNOUNCE_ADVANCEMENTS)) {
               this.playerList.broadcastMessage(new TranslatableComponent("chat.type.advancement." + p_135989_.getDisplay().getFrame().getName(), this.player.getDisplayName(), p_135989_.getChatComponent()), ChatType.SYSTEM, Util.NIL_UUID);
            }
         }
      }

      if (advancementprogress.isDone()) {
         this.ensureVisibility(p_135989_);
      }

      return flag;
   }
   ...

If we look at the above class, we can see that no checks are carried out to check the game mode of a player who's awarded an advancement, resulting in players of any game mode being able to earn them.

Avoma 2022-03-14T16:06:53Z

Can confirm in 1.18.2.

Avoma 2022-06-30T15:11:51Z

Can confirm in 1.19.

Avoma 2022-08-20T10:20:03Z

Can confirm in 1.19.2.

Jon1337 2023-09-04T11:05:05Z

In 23w35a

tehbeard 2025-01-06T12:41:45Z

Correct fix would IMO be adding a predicate to the existing advancements for survival/adventure mode, rather than hard coding a check for spectator mode; as advancements are often used by datapacks as an event system to trigger functions based on player actions.