Replication-system selector

Generic Replication

Use by default. It supports replicated actors, properties, RPCs, relevancy, priority, update frequency, dormancy, components, and subobjects. Most UE networking documentation assumes it.

Remain on Generic Replication when actor/connection counts fit the server budget and its model meets the game's filtering needs. Tune content and dormancy before replacing the driver.

Replication Graph

Evaluate when the server must repeatedly build per-connection replication lists for large actor and connection counts. RepGraph keeps persistent graph nodes/lists that share work across frames and connections.

Adoption gate:

• a Network Insights/server trace shows replication-list gathering or per-connection actor evaluation is a material bottleneck;
• actor categories have clear spatial, always-relevant, owner-only, team, or dormancy rules;
• the team can implement and test custom graph nodes;
• the project accepts Beta maturity;
• console split screen is not required, because Epic documents that limitation.

Iris

Iris is compiled into UE but is not the default replication system. UE 5.8 marks it Experimental. It changes relevancy into filtering and priority into Iris prioritization, shares quantized replicated state work, and aims for stronger scalability/concurrency.

Adoption gate:

• a specific Iris capability or measured scale need justifies Experimental risk;
• all plugins/subsystems and custom serializers are compatibility-tested;
• replicated subobjects use the registered subobject list;
• migration differences are documented and both network correctness and performance are tested;
• rollback to Generic Replication is planned until the shipping gate is passed.

Do not select Iris because it is newer. Do not assume Generic settings map unchanged: consult the 5.8 migration guide.

Selection output

Return:

Candidate	Measured need	Maturity/constraint	Decision
Generic	baseline	default/stable path	use/reject
RepGraph	large actor x connection filtering cost	Beta; console split-screen limitation	use/reject
Iris	specific filtering/prioritization/scalability need	Experimental; migration work	use/reject

No selection is complete without a representative server trace and target-player-count test.