Revision history: Collaboration event

A collaboration event (collab) is a limited crossover in which characters or items from an external franchise appear in a gacha game. Collabs are marketing spikes for both sides, and mechanically they tend to come with special rules that this wiki tracks because they trip up cost planning.

The recurring pattern: collab characters run on a separate banner category whose pity pool is isolated from regular banners. Progress built on a collab banner does not transfer out when the event ends, and vice versa. Honkai: Star Rail's Fate/stay night collaboration (from Version 3.4, July 2025) works this way, [1] and Wuthering Waves' Cyberpunk: Edgerunners collab (June 2026) even used a dedicated pull currency.

The second recurring rule is permanence: collab characters usually never enter the standard pool and rerun rarely or never, since reruns require re-licensing the IP. Communities treat collabs as now-or-never pulls for that reason, and older games carry folklore about missed collab units that never returned.

Historically, license-heavy games built entire calendars on collabs; the model runs from early Japanese social games through modern examples across the genre. For players the practical checklist is stable: confirm whether the pity pool is shared, whether the currency is separate, and whether any unit is given free during the event.