Iron Curtain — Design Documentation

D036: Achievement System

Decision: IC includes a per-game-module achievement system with built-in and mod-defined achievements, stored locally in SQLite (D034), with optional Workshop sync for community-created achievement packs.

Rationale:

• Achievements provide progression and engagement outside competitive ranking — important for casual players who are the majority of the C&C community
• Modern RTS players expect achievement systems (Remastered, SC2, AoE4 all have them)
• Mod-defined achievements drive Workshop adoption: a total conversion mod can define its own achievement set, incentivizing players to explore community content
• SQLite storage (D034) already handles all persistent client state — achievements are another table

Key Design Elements:

Achievement Categories

Storage Schema (D034)

CREATE TABLE achievements (
    id              TEXT PRIMARY KEY,     -- "ra1.campaign.allied_hard_complete"
    game_module     TEXT NOT NULL,        -- "ra1", "td", "ra2"
    category        TEXT NOT NULL,        -- "campaign", "skirmish", "multiplayer", "community"
    title           TEXT NOT NULL,
    description     TEXT NOT NULL,
    icon            TEXT,                 -- path to achievement icon asset
    hidden          BOOLEAN DEFAULT 0,    -- hidden until unlocked (surprise achievements)
    source          TEXT NOT NULL         -- "builtin" or workshop resource ID
);

CREATE TABLE achievement_progress (
    achievement_id  TEXT REFERENCES achievements(id),
    unlocked_at     TEXT,                 -- ISO 8601 timestamp, NULL if locked
    progress        INTEGER DEFAULT 0,    -- for multi-step achievements (e.g., "win 10 matches": progress=7)
    target          INTEGER DEFAULT 1,    -- total required for unlock
    PRIMARY KEY (achievement_id)
);

Mod-Defined Achievements

Mod authors define achievements in their mod.toml, which register when the mod is installed:

# mod.toml (achievement definition section in a mod)
[[achievements]]
id = "my_mod.survive_the_storm"
title = "Eye of the Storm"
description = "Survive a blizzard event without losing any buildings"
category = "skirmish"
icon = "assets/achievements/storm.png"
hidden = false
trigger = "lua"    # unlock logic in Lua script

[[achievements]]
id = "my_mod.build_all_units"
title = "Full Arsenal"
description = "Build every unit type in a single match"
category = "skirmish"
icon = "assets/achievements/arsenal.png"
trigger = "lua"

Lua scripts call Achievement.unlock("my_mod.survive_the_storm") when conditions are met. The achievement API is part of the Lua globals (alongside Actor, Trigger, Map, etc.).

Design Constraints

• No multiplayer achievements that incentivize griefing. “Kill 100 allied units” → no. “Win 10 team games” → yes.
• Campaign achievements are deterministic — same inputs, same achievement unlock. Replays can verify achievement legitimacy.
• Achievement packs are Workshop resources — community can create themed achievement collections (e.g., “Speedrun Challenges”, “Pacifist Run”).
• Mod achievements are sandboxed to their mod. Uninstalling a mod hides its achievements (progress preserved, shown as “mod not installed”).
• Steam achievements sync (Steam builds only) — built-in achievements map to Steam achievement API. Mod-defined achievements are IC-only.

Alternatives considered:

• Steam achievements only (excludes non-Steam players, can’t support mod-defined achievements)
• No achievement system (misses engagement opportunity, feels incomplete vs modern RTS competitors)
• Blockchain-verified achievements (needless complexity, community hostility toward crypto/blockchain in games)

Phase: Phase 3 (built-in achievement infrastructure + campaign achievements), Phase 6b (mod-defined achievements via Workshop).