Power Up system: How it works

Power Ups Explorer

How to use the explorer

Pane 1:

• Scroll or search to select a champion, which will show their Power Up lists in the main pane.

Pane 2:

• Use the Stage, Level and Traits filter buttons to reveal odds for each available Power Up on the selected champion. Odds are per shop (see note below), with the max being 50% due to the no repeat rule.

• Setting Traits to Off simulates benching the target unit's traits to avoid being offered Classy or trait-specific Power Ups (e.g. Star Sailor).

• For each listed Power Up, shows all relevant tags which affect either the odds or the conditions to be offered it.

• Hover or click on a Power Up name in the main pane to show its details in the right pane.

• Hover over tags like Weight and Common to see what they mean.

Pane 3 (hidden on mobile/small windows):

• Shows the selected Power Up's effect and which champions it can appear on, as well as the range of odds for that Power Up on each of those champions.

• Click on a champion icon to switch to it in the main pane.

Disclaimer

• Odds shown are calculated using a model based on data gathered from in-game testing and our understanding of how the system works. Since it is practically impossible to get enough data for every champion in every scenario, we cannot guarantee accuracy but we are confident that this model is a big step forward.

• Odds shown are the long term probability per shop, they should not be used to estimate the odds from shop to shop. You can use the rules below to calculate the odds in specific scenarios.

10 simple rules

The system aims to offer some variety in each shop, but not too many niche options.

1) No repeats between consecutive shops for the same champion

2) Cannot offer duplicates in the same shop

3) Slots 1 and 2 are always Primary, Slot 3 can be Primary or Secondary

4) Avoid triple Common shops if possible

5) Weight is relative, higher is more likely

6) Cannot offer more than 1 of each per shop of Multiple, Stacking, Weird, Trait tags

7) Cannot offer a Power Up that is already active on your team, unless it has Multiple tag

8) Looks at your current board (can bench traits to reduce pool)

9) Duplicate entries of the same Power Up in a champion’s lists do not increase odds

10) List order matters (boost effects at the end of each list)

What we know from the game files

• As shown in the explorer, each champion has ordered lists marked Primary and Secondary, showing the Power Ups that can be offered to them.

• Each Power Up has different values for Weight, Min Level, Max Level, Min Stage, Max Stage, Trait Active, Trait Level, Min Player HP, Max Player HP, Multiple, Common, Stacking, Weird to determine the conditions of when it can be offered.

• There are also more tags such as Duo and Role, but they do not seem to affect the odds of being offered so they are not shown in the explorer.
  
  

Rules 1 and 2: The unbreakable rules

• The 'no repeats' and 'no duplicates' rules are straightforward, limiting the available pool for each slot. However, their inflexibility means that they are the main cause of the bugs where less than 3 options can be offered (even 0).

• When a champion's pool of available Power Ups is small (e.g. Stage 3 Shen Hero only has 5 available), the previous shop with 3 options forces the next one into a situation where it is impossible to fill every slot while satisfying every rule.

• The slots are filled one by one from Slot 1 to Slot 3, checking the rules at each step. If it hits a slot that cannot be filled, the shop offers only the previously validated slot(s).
  E.g. if there is only one Primary left in the pool for that shop it will appear in Slot 1, but Slots 2 and 3 do not appear (even if there are valid Secondary options for Slot 3). If there are no available Primary options for that shop, 0 slots appear (even if there are valid Secondary options for Slot 3). The little evidence we have suggests that Slot 3 is still rolled in these two scenarios (impacting the next shop), but the result is never shown.

Rule 3: Primary vs Secondary lists

• Every champion’s Primary and Secondary lists are different. Power Ups can be Primary on some champions but Secondary on others.

• Primary options are mean to be more common and takeable in most scenarios, while Secondary options are more niche.

• Since Patch 15.5, Slots 1 and 2 in the shop can only offer Power Ups from a unit's Primary list.
  Slot 3 draws from available Power Ups in both the Primary and Secondary lists.

• Previously, this 2 Primary setup was only true for tank classes. E.g. that was why Socialite could only be offered in Aatrox’s third slot (it was Secondary for him). All other classes were only guaranteed one Primary, in slot 1.

• There is no evidence of any odds manipulation for Primary vs Secondary in Slot 3.

Rule 4: Common vs unCommon

• This is a similar idea to Primary/Secondary, except that the effect of being Common or not Common (we'll refer to that as unCommon) is same across all champions.

• You will be offered mostly Commons, purely due to the fact that most Power Ups are Common. But it would be boring to get too many Commons, so the system tries to always offer at least one unCommon, artificially reducing the rate of triple Common shops (still possible but much rarer).

• We think that if Slots 1 and 2 are Commons, then Slot 3 is rerolled up to a certain number of times to try and hit an unCommon in that slot. If the reroll limit is reached, or if there are no unCommon ones left in the pool, a triple Common shop is offered.

• Somewhat ironically, the overall result is that unCommons are actually more common than corresponding Commons when looking at individual appearance rates.

• Proof 1: From Stage 3 onwards, Xin Zhao’s available Primary pool is entirely Common. If our theory is correct, then the last slot must always be both Secondary and unCommon.
  Our data 100% aligned with this: Slots 1 and 2 were always Primary, and Slot 3 was always a Secondary unCommon. Inner Fire and Singularity (his Secondary Commons) were never offered. In the explorer, we have shown nominal odds of 0.5% to show that it is still theoretically possible to get these from maxing out the reroll limit.

• Proof 2: From Stage 3 onwards and when neither of her traits are activated on the board, Yuumi’s only unCommon Power Up is Keen Eye (Secondary). In this scenario, Slot 3’s only valid option is always Keen Eye. However, due to the no repeats rule, it cannot be offered in every shop. Instead, Keen Eye is always offered in alternating shops, with every other shop being triple Common.

Rule 5: Worth the Weight?

• Weight is the relative probability of drawing one Power Up compared to another. The Weights that are currently used are (zero), 5, 10, 15, 20.

• In a vacuum, a Power Up with a weight of 20 has double the odds of appearing compared to one with a weight of 10. However, in practice this doesn’t often happen, due to all the other rules at play in the system.

Rule 6: Unique tags

• Power Ups with the Multiple, Stacking, Weird and Trait tags have a one-per-shop limit.

• E.g. you can be offered one Stacking and one Weird in the same shop, but you cannot be offered two Stacking Power Ups in the same shop.

• The only Trait Power Ups affected by this rule are Mech Pilot and Robo Ranger.

• Multiple means that you can have more than one champion with the same Power Up on your team at the same time (e.g. Fan Service).

• Not all Power Ups have been tagged as you might expect. E.g. Hat Trick doesn't have the Stacking tag, and Doublestrike is a Multiple even though it doesn't have a two-tiered effect.

Rules 7 and 8: Ways to thin the pool

• Rule 7: You cannot be offered a Power Up that is already active on one of your other units, unless it has the Multiple tag.

• E.g. if you currently have Drift Duo (not Multiple) active on Lucian, you cannot get Drift Duo if you use your other Power Snax on Senna.

• If your APM is good and you can spare 2 Power Snax (temporarily), you can use this rule to exclude an unwanted Power Up on your target unit, to increase the odds of getting better options. Use the explorer to see which unwanted options have the highest odds, and which helper units have the best odds of getting it.

• E.g. if you want to exclude Ramping Rage on Jinx, you can cycle your first Power Snax until you hit it on a helper unit (Senna has high odds on Stage 4), before using your second Power Snax on Jinx. Then you sell the helper unit so you can Power Up your tank.

• Rule 8: The system looks at your current board (not previous round like other mechanics) to determine what can be offered.

• This rule mainly applies to Classy and Trait Power Ups (e.g. Star Sailor) — you can bench the traits of your target unit to exclude these Power Ups from their pool. Use the Traits On/Off toggle in the explorer to see the difference.

• Since Patch 15.5, Classy can only be offered if the silver-tier of the relevant trait is active on your board. The relevant trait and tier are shown in the explorer (e.g. 4+ Heavyweight for Jayce).

• Trait Power Ups require the trait to be active on your board in order to be offered, from Stage 3 onwards. Before that, they are always available regardless of your board situation, so they cannot be excluded. This may be changed at a later date.

• It has been suggested that Power Ups with anti-heal and Shred/Sunder effects should be automatically excluded if you already have items with those effects. This currently has not been implemented as far as we know.

Rule 9: Duplicate entries in Primary/Secondary lists

• Some champions have duplicate Power Ups in their Primary and/or Secondary lists. E.g. Seraphine has Class twice in her Primary list, Ahri has Solar Breath twice in her Secondary list, Rammus has Bestest Boy in both his Primary and Secondary lists.

• For a duplicate Primary, only the first entry is kept.
  For a duplicate Secondary, only the first entry is kept.
  For a duplicate across Primary and Secondary, only the Secondary is kept.

• Due to these deduplication rules, having more than one entry does not increase the odds of that Power Up appearing.

Rule 10: Are certain Power Up odds boosted?

• Since PBE, some players have noticed that some Power Ups seem to be offered much more often than expected (e.g. Socialite on Aatrox despite being a Secondary).

• This boost effect was fairly consistent in the data across champions, applying mainly to Power Ups at the end of the Primary/Secondary lists (in the list order from the game files).

• Our data suggests that both the last (strong boost) and second-to-last (weak boost) valid entries in the Primary and Secondary lists are boosted. But since the weak boost is smaller, it may not actually exist and is just due to sample sizes.

• E.g. in the explorer, look at Stage 1 Ezreal. His last 3 Secondary are all Weight 10 and Common, but we think that Final Form receives a strong boost and Fairy Tail gets a weak boost, compared to Sky Piercer. On Stage 3, Final Form is no longer available, so Fairy Tail becomes the last valid entry and receives the strong boost and Sky Piercer gets a weak boost.

• This rule is the most uncertain in our model, partly because we still don't know why it occurs.
  The explorer uses the boost amounts that best fit our data.

Conclusion

The 10 rules are easy to understand, but it is difficult for players to gauge actual odds after considering all the interactions, which is why we created the explorer.

There is enough info in the explorer and this page for you to develop your own models, if you have a different understanding of the system or you are a budding game designer.

Comments or questions?