# Investment of the Chain Master
*Source: Player's Handbook (2024) p. 156*
**Prerequisite**: Level 5
When you cast [Find Familiar](Mechanics/CLI/spells/find-familiar-xphb.md), you infuse the summoned familiar with a measure of your eldritch power, granting the creature the following benefits.
## Aerial or Aquatic
The familiar gains either a [Fly Speed](Mechanics/CLI/rules/variant-rules/fly-speed-xphb.md) or a [Swim Speed](Mechanics/CLI/rules/variant-rules/swim-speed-xphb.md) (your choice) of 40 feet.
## Quick Attack
As a [Bonus Action](Mechanics/CLI/rules/variant-rules/bonus-action-xphb.md), you can command the familiar to take the [Attack](Mechanics/CLI/rules/actions.md#Attack) action.
## Necrotic or Radiant Damage
Whenever the familiar deals Bludgeoning, Piercing, or Slashing damage, you can make it deal Necrotic or Radiant damage instead.
## Your Save DC
If the familiar forces a creature to make a saving throw, it uses your spell save DC.
## Resistance
When the familiar takes damage, you can take a [Reaction](Mechanics/CLI/rules/variant-rules/reaction-xphb.md) to grant it [Resistance](Mechanics/CLI/rules/variant-rules/resistance-xphb.md) against that damage.