Chimera Battle - Type Chart, Move Sets, Status & Battle AI for RPG Maker MZ

Your creatures fight. But nobody has to think about it.

The capture works. The collection works. Then the player walks into a battle, presses Attack four times, and wins — and does that for the next thirty hours.

Nothing about which creature they brought mattered. Nothing about which move they picked mattered. The fight was a speed bump, not a decision.

That is not a balance problem. It is a missing system problem. Every creature-collector that holds a player runs on the same four things, and RPG Maker MZ ships none of them:

• A type chart the player learns to read.
• Moves with limited uses, so a boss is a resource problem.
• Status effects and stat stages, so a fight has a shape.
• An opponent that punishes a bad matchup.

Chimera Battle adds all four — without replacing RPG Maker's battle system, and without touching a single skill you have already built.

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What it does

A real type chart, and the player can see it

18 types by default, fully editable, with same-type attack bonus, compounding dual types and true immunities. Fire hits Grass for double; a Ghost cannot be touched by Normal at all.

And while the player is choosing a target, a live preview tells them exactly what is about to happen — ×2 Super effective, ×½ Not very effective — with the move's type and the defender's types shown as coloured labels. A mechanic the player cannot see is a mechanic they never learn to play around.

Move sets with real PP

Every move gets its own uses, per creature, separate from MP and TP — because a creature-collector wants "Flamethrower, 15 uses", not a shared pool. The skill list shows type and PP 12/15 at a glance, turning amber when a move runs low and red at zero. Level-up learnsets, four-slot movesets, and the "forget a move?" prompt that makes them interesting.

Status effects that change how a fight is played

Burn, poison, paralysis, sleep, freeze and confusion. Burn cuts physical attack only, so it counters physical attackers specifically rather than being a flat debuff. Paralysis halves speed and sometimes eats the turn. Freeze thaws on a chance, not a timer. Confusion rides alongside a major status and makes the creature hit itself.

Types grant immunity. A Fire creature cannot be burned. A Steel creature cannot be poisoned. RPG Maker has no type system, so no other plugin can do this.

Stat stages, −6 to +6

The genre-standard buff curve, bounded at ×0.25 and ×4, applied on top of whatever RPG Maker already computed — so your traits, buffs and equipment all still count. Growl really does drop the enemy's Attack, the battle log says so, and the next hit is measurably weaker.

An AI that reads the matchup

Four difficulties. Smart maximises expected damage, so it respects your types, your stat stages and your status. Expert additionally prefers a reliable knockout — given two lethal options it takes the accurate one, not the flashy one.

Tested, not asserted: given two moves of identical power differing only in type, the AI chose the Water move 30 out of 30 times against a Fire target, and the Fire move 30 out of 30 against a Grass one.

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It will not break your project

A skill with no <chimera type:> notetag is left completely alone.

Install this into a finished game and no existing skill changes its damage by a single point. You opt each skill in, one notetag at a time. Every core method is extended through a saved original, never replaced, so other plugins in the chain keep working.

Statuses are your database states, not a private system — so state icons, cure items, the state UI and every other plugin you own carry on working normally.

Setup is three notetags

<chimera types: Fire, Flying> on the creature.
<chimera type: Fire>, <chimera power: 90>, <chimera category: special>, <chimera pp: 15> on the skill.
<chimera effect: status burn chance 10> for a rider.

And typos are reported, naming the offending text and the skill it came from — not silently ignored into a move that mysteriously does nothing.

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Built to a standard

• 133 automated tests, all green, every one written before the code that satisfies it. The whole engine is pure logic and runs outside RPG Maker.
• Deterministic by construction. Every roll — damage spread, criticals, status procs, sleep duration, thaw, AI tie-breaks — draws from a seeded generator. Math.random() is never called in battle logic. The same seed replays the same battle exactly.
• Measured in the real engine. Whole battle scene: 5.38 ms per frame, 32% of the 16.67 ms budget, 0 frames over budget in 599 sampled. The matchup preview costs 0.15 µs per frame because it only redraws when the matchup changes.
• Zero allocation in the hot paths. The type chart is one flat 324-byte array — a lookup is a single indexed read. Notetags are parsed once and cached; no regular expression ever runs inside a damage roll.
• Raw, readable source. Nothing minified, nothing obfuscated. Full JSDoc on every public function. You bought a tool you can read, debug and extend.

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Works with Chimera Core

Chimera Battle is standalone and needs nothing else. But if you also own Chimera Core, genetics stop being cosmetic and start deciding fights: IVs, training and natures feed straight into the damage formula, so two creatures of the same species at the same level hit for genuinely different amounts.

The player who bred for a +Attack nature finally finds out it was worth it.

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What's in the box

• ChimeraBattle.js — the engine. Types, moves, PP, status, stat stages, damage, turn resolution, AI, save/load, and the full RPG Maker MZ integration.
• ChimeraBattleUI.js — type labels, PP display and the matchup preview. Purely cosmetic; turn it off and the engine is unchanged.
• Readme_for_Users.md — install, one-minute setup, the complete notetag reference, the full script API, balancing guidance, a compatibility table and troubleshooting.
• LICENSE.txt — unlimited games, commercial or free, 100% of your revenue.

Requires: RPG Maker MZ. No dependencies, no install step, no account.

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The rest of the Chimera line — all three now available

Chimera Core — IV genetics, breeding inheritance, branching evolution and virtualised box storage.

Chimera Field — biome spawn tables, rarity tiers, level bands, variant rates and a Field Guide that records where each creature lives. It decides which species you meet and at what level; this plugin decides how that fight goes.

Each is an independent plugin that runs alone. Together they share the same <chimera species: N> notetag, so a project tagged for one is tagged for all.

Get all three in the Chimera Suite bundle →

Licence

Use it in unlimited games, commercial or free. Keep 100% of your revenue — no royalties, ever. Modify the source however you like. Just don't resell the plugin itself.

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Built by CSAF. Also available: Chimera Core — creature genetics, breeding, branching evolution and box storage for RPG Maker MZ.

Chronicle Core — branching quests, choices that foreclose, faction reputation & world state