How it works
How Last Epoch decides which drops to show, why that's hard to test in-game, and how this tool checks a filter instead.
How the game reads a filter
For every drop, the game goes through the filter's rules from the top of the in-game list:
- Disabled rules are skipped.
- The first rule whose conditions all match decides. It shows or hides the item and sets its color, sound, beam and map icon. Rules below it are never checked for that item.
- If no rule matches, the item is shown.
Within a rule, every condition must match. Within one condition, any of the selected values is enough: a rarity condition with Rare and Exalted selected matches both.
A rule with no conditions matches every item, which is how most filters end with a catch-all HIDE. Keys, runes, glyphs, shards and other consumables are the exception: only rules with a consumable condition apply to them.
Example
An exalted ring drops with T7 Health and T6 Endurance. The filter has four rules:
| # | Rule | The ring |
|---|---|---|
| 1 | SHOW: any of 20 chase uniques | Not a unique: no match |
| 2 | HIDE: Normal or Magic rarity | Exalted: no match |
| 3 | SHOW: at least 2 of Health, Spell Damage, Fire Resistance and nine other affixes, at tier 6 or higher | Only Health is on the list: no match |
| 4 | HIDE: no conditions | Matches: hidden |
Adding Endurance to rule 3 would show the ring. Nothing in the game points out the gap: the ring simply never appears.
Things that surprise people
The tool follows these behaviors. Some are confirmed in-game; the rest are the best current understanding of the game and still need an in-game test.
- A catch-all HIDE doesn't hide keys, runes, glyphs, shards or other consumables. Only a rule with a consumable condition can hide them. Confirmed in-game
- An affix condition with no affixes selected counts every affix, idol affixes included. Confirmed in-game
- Bases picked for an item type stop counting once the condition has a second item type: every base of the selected types matches. Not yet confirmed in-game
- Turning Advanced off on an affix condition ignores the tier settings it still stores, but the minimum number of matching affixes still applies. Not yet confirmed in-game
- A class condition matches only items with a class requirement; ordinary bases never match it. Not yet confirmed in-game
- A rarity or class condition with nothing selected matches nothing. Not yet confirmed in-game
Where the tool can't tell how the game treats a condition at all, such as item-level and faction conditions, it marks the result uncertain and names the rule to check in-game.
Why filters are hard to test
In the game, the only way to test a rule is to see an item drop and check whether its label appears. That works for common items. The items a filter must never hide are the rare ones: a chase unique, or an exalted item with two high-tier affixes you want. Two exalted affixes on one item are rare, and one particular pair is rarer still, so you can't farm your way through a test.
And there are a lot of them. The game has more than 400 uniques, many of them on several bases, and more than 50,000 combinations of two exalted affixes across equipment types, before counting items with three or four.
A hidden item leaves no trace: nothing appears on the ground, and nothing tells you that anything dropped. A mistake can go unnoticed for a whole season.
And mistakes are normal. A filter can have up to 200 rules, and a rule can go wrong in many ways:
- a SHOW rule placed below a broader HIDE rule, so it never gets a chance
- a section turned off while leveling and never turned back on
- an affix list made before a patch added new affixes
- a change to someone else's filter without knowing how its rules depend on each other
What the tool does instead
A filter is saved as an XML file: a plain list of rules with exact conditions, so it can be checked without the game. The tool reads the file and runs test items through a model of the game's matching, the same top-down walk described above:
- each selected chase unique on every base it can drop as, at its worst: lowest rolls, legendary potential and Weaver's Will, uncorrupted and corrupted, plus Legendary copies of uniques that can drop as Legendary
- every combination of up to three T6 and T7 affixes (four in the settings) on every equipment type
- keys, runes, glyphs, shards, other consumables, Harbinger's Needle and cocooned items
- whole item types, such as every Idol Altar
Testing every affix one by one would take far too long, but a filter can tell affixes apart only by the lists it names them in. Affixes that appear in exactly the same lists and can roll in the same places behave the same in every rule, so the tool tests one of each group and still covers every combination.
Each hidden item comes with the rule that hides it and why the SHOW rules above it didn't match. The tool can also turn a single rule on or off and show what changes, and it points out rules that can never fire and affix lists that are missing affixes.
Limits
- It's a model of the game, not the game. Where the game's behavior is unknown, results are marked uncertain instead of guessed.
- Patches can change both the game data and how rules work. The game data is updated after patches; its version and date are shown at the top of the main page.
- A hidden item is a finding, not necessarily a mistake: filters hide things on purpose.