Your main skill is tied to Path of Exile 2 Currency your weapon

The weapon's support slots dictate how many supports can be active

You still insert support gems into those support slots—but they’re part of the item, not the armor.

This leads to:

Fewer gem-swapping issues

Simplified gearing around key skills

Incentivized weapon crafting

How Do Support Gems Interact with Skills?
Support gems will only affect an active skill if:

The gem is compatible (e.g. Multistrike won’t work with a projectile spell).

It’s placed in a valid support slot connected to the skill.

You can inspect whether a support gem applies to a skill via its tooltip—if it modifies the skill, it will list how.

Support Tag Types:
Spell

Attack

Projectile

Minion

Totem / Trap / Mine

Elemental / Physical / Chaos

A support gem with the “Projectile” tag won’t work on a melee skill unless it converts into a projectile.

Modifier Effects from Support Gems
Support Gems can:

Add Damage (flat or percentage-based)

Change Damage Type (e.g., Elemental Conversion)

Change Skill Mechanics (e.g., Chain, Fork, Split)

Increase Cast/Attack Speed

Modify Resource Cost

Add Conditional Effects (e.g., bonus damage against chilled enemies)

These modifiers can stack, but there are often diminishing returns or limitations. For example, if you support a skill with multiple damage-enhancing gems, the mana cost may become excessive or cooldowns may be longer.

Limits and Drawbacks of Support Gems
Support gems often come with trade-offs, which are crucial to managing build efficiency:

Increased Mana/Resource Cost
Many supports increase the skill’s cost significantly.

Reduced Damage Efficiency
Some supports, like Greater Multiple Projectiles, lower base damage in exchange for more projectiles.

Complex Scaling
More supports = more interactions. It's easy to oversupport a skill and end up with inefficient or buy POE 2 Orbs conflicting modifiers.