Dev Diary: Endurance, Frenzy and Power Charges

This week we’ve unveiled Charges – an important combat mechanic in Path of Exile. These can be accumulated in combat, and are represented by glowing orbs that orbit the character until they are consumed or fizzle out. Each attribute has its own type of Charge, which grants a specific property while Charges of that type are active. Various skills and items help you accumulate Charges and gain additional benefits from them.

Our Charge System

We felt that we could improve this system. We wanted Charges to be a viable (but optional) build for any class in the game. To encourage them as an optional choice, we’ve added a lot of Charge-related passive skills that players can choose to specialise in. Because of our strong emphasis on itemisation, it was important for us to design items that could interact with Charges for characters that wanted to specialise. Finally, we wanted to make sure that Charges actually did something passively, so that they weren’t useless if taken out of the context of the skills that grant or consume them.

Charges are granted when one of the conditions imposed by an active skill, passive skill or item is met. For example, there are passives that can grant Charges when you score critical strikes. Many active skills grant Charges when you hit or kill monsters with that skill.

Each class has a natural limit of the number of Charges of each type that they can have. A primary character class such as the Marauder can have more of their native Charge type than a hybrid class (which is allowed an increased quantity of two types of Charges). These values can be increased via passive skills.

If no new Charges of that type are accumulated within a certain time limit, those Charges dissipate and are lost. When a skill that consumes Charges is used, Charges of the appropriate type are removed for an additional effect per Charge. For example, the Immortal Call skill consumes Endurance Charges to grant a period of invulnerability proportional to the number of Endurance Charges consumed.

Items and passive skills can also affect Charges. For example, there could be a unique ring that grants one additional maximum Frenzy Charge and a bonus of some additional accuracy per Frenzy Charge. We have dozens of passive skills that alter the conditions that Charges are granted, their effects, or the quantity of them that a player is allowed.

Encouraged Player Behaviour

The most obvious player behavior that stems from Charges is that players spend more time in combat. Because they are anxious about their Charges vanishing, they are more likely to engage a second group of foes immediately after the first. We're always trying to find game mechanics that encourage players to play Path of Exile in an action-packed way rather than kiting single enemies around, so this is a win for us.

We're always trying to design game mechanics where players constantly have to make important split second decisions based on situational factors such as monster position, health status and now, Charges.

A less obvious benefit is that the Charges system encourages players to use multiple skills - some to charge up and some to consume them. It's amazing how many players play action RPGs using only a single skill. Although we are happy for players to specialise, it's good to provide encouragement to those who want to seek inter-skill synergy.

The Charges system also opens up a wide design space for passive skills that players can invest in to further synergise with. For example, we could have passive skills that:

• Grant an Endurance Charge when you block an attack
• Grant a Frenzy Charge when you kill three foes within two seconds using a weapon
• Grant a Power Charge when you hit ten foes with one spell

Having a wide variety of passive skills and items that interact with the Charges gained from these active skills also allows players to specialise in Charges to a very large degree if they choose. Where possible, we try to add obvious build routes such as these so that players have many paths to build around when experimenting with which gameplay style suits them best.

Of course, it's worth mentioning that players don't have to use Charges if they aren't interested in them. There are plenty of other skills and combat options for players who prefer different styles of gameplay.

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