effect · add_tech_bonus

Hands-On Usage

add_tech_bonus is commonly used in focuses, decisions, or events to provide players with research acceleration bonuses in specific technology tree fields. For example, completing a military focus might grant a research discount on armor or naval technologies. Its "limited uses" characteristic makes it ideal for simulating historical technological advantages during specific periods without creating permanent balance issues.

focus = {
    id = GER_panzer_doctrine
    ...
    completion_reward = {
        add_tech_bonus = {
            name = GER_panzer_bonus
            bonus = 0.5
            uses = 1
            category = armor
        }
    }
}

Synergy

• [add_research_slot](/wiki/effect/add_research_slot) — Adds research slots while granting tech acceleration bonuses, commonly paired in dual research reward combinations upon powerful focus completion.
• [add_ideas](/wiki/effect/add_ideas) — Distributed together with national spirits, forming a complete focus reward package of "research acceleration + sustained passive buffs."
• [has_completed_focus](/wiki/trigger/has_completed_focus) — Used for conditional checks to ensure tech bonuses in subsequent events only trigger after prerequisite focuses are completed, preventing premature reward release.
• [add_doctrine_cost_reduction](/wiki/effect/add_doctrine_cost_reduction) — When players need to simultaneously reduce doctrine research costs, combining both effects creates comprehensive military technology incentives.

Common Pitfalls

1. Omitting the name field: name is the unique identifier for a bonus. If the same name is used in multiple places, the game treats them as a shared reward pool with combined uses, causing unexpected bonus depletion. Always assign non-duplicate names to each independent bonus.
2. Mistakenly treating category and specific technologies as interchangeable with no restrictions: The scope of category differs from the specific technology field. Entering non-existent categories or spelling errors causes the bonus to silently fail with no error message. Manual verification in the research interface is required during testing to confirm bonuses display correctly.