Concept: Combo System

The combo system chains discrete abilities into designer-authored, branching sequences. It is structured the opposite way from most UE combo solutions: each step is its own ability, and a separate graph asset describes how steps chain.

Optional and off by default

Nothing combo-related exists until you enable it - see How-To: Get the Building Blocks step 7.

Why one ability per step

The step owns its montage, its damage, its costs, its cooldown and its augment slots, because it is a normal ability and GAS already handles all of that. The graph owns only the topology: which step follows which, on what input, under what conditions.

The trade-off is real and worth stating: one activation per step means one ServerTryActivateAbility per step, plus the controller's own transition RPC. A four-hit string is more round trips than a single ability looping through montage sections would be. In exchange every step gets per-step gameplay data for free.

The three layers

Layer	Lives in	Holds
Topology	The combo graph asset	Steps, transitions, entry handshake, end points.
Per-step numbers	The step node	Phase boundaries, transition window, buffer overrides, events.
Execution	The step ability	Montage, damage, cost, cooldown, augments.

Runtime flow

text

rooting ability activates
  -> controller arms a root watcher for its cancel window
  -> player presses; the press is buffered and matched against the starting handshake
  -> StartCombo -> EnterNode: activate the step ability, open its transition window
  -> a matching press inside the window fires a transition -> EnterNode again
  -> an End node reaches ComboCompleted; a closed window with nothing queued resets

Where conditions fit

Each transition may carry conditional augments gated by a UCrimsonComboTransitionCondition. The condition observes the current step and decides at fire time whether the reward is granted - the difference between "you pressed in time" and "you actually connected". See How-To: Gate Combo Branches with Conditions.

What it does not do

It does not play montages - the step ability does.
It does not read AnimNotifies. Windows are authored numbers scaled by play rate, not notify-driven, so a missed notify on a dedicated server cannot desync the combo.
It does not run on simulated proxies. Remote players see combos through the replicated ability montages only.