ONI Games · Published What actually happens in an idle RPG: how damage is calculated, why bosses stop you, how gear, summoning and rebirth fit together, and what to upgrade first. With real numbers from two idle RPGs we made.
An idle RPG is a role-playing game where the fighting happens without you. Your heroes attack on their own, stage after stage, and your job is to make them stronger between fights: level them up, equip them, combine them and decide when to push, farm or start over. Under the art, almost every idle RPG runs on the same handful of systems.
The core loop: heroes deal damage, damage clears stages, stages pay gold and loot, gold and loot make heroes stronger. Bosses are the checkpoints, and rebirth is the reset that keeps it all moving.
We make two idle RPGs, Idle Ronin: Cyber RPG and Idle Summoner: Pixel RPG, so we will use their real numbers to show how each system works. For a gentler introduction, start with what is an idle RPG.
Heroes and stats: where damage comes from
Every idle RPG boils down to one number: how much damage your team deals per second (DPS). It is built from a few stats:
- Attack (ATK): the base damage of each hit.
- Attack speed: how often you hit.
- Critical chance and critical damage: how often a hit is a critical, and how much extra it deals.
- Multipliers: percentage bonuses from rebirth, gear, sets and skills, which multiply each other.
The last point matters most. A +10% bonus on top of other bonuses is worth more than it looks, because bonuses multiply rather than add. In Idle Ronin, for example, every Rebirth Token adds 10% ATK, every skin beyond the first adds 10% ATK to all units, and a unit's ATK doubles at level 50, doubles again at level 100 and keeps climbing.
Stages, waves and bosses
Progress in an idle RPG is measured in stages. In Idle Ronin every stage has 10 waves and the tenth is a boss; in Idle Summoner every stage has ten castles and the tenth holds the boss. Normal enemies are there to pay gold. Bosses are the test.
Two things make bosses the real checkpoints:
- They have far more health. In Idle Ronin a boss has 6 times the health of a normal enemy of its stage, and 10 times on every stage ending in 4 or 9 from stage 10 on. That is why players get stuck on stages like 14, 19 and 24.
- They have a timer. You must win before it runs out: 30 seconds at the start in Idle Ronin, about 30 in Idle Summoner. Enough damage, not enough time, means a loss.
Losing to a boss costs nothing in most idle RPGs. Both our games send you back to the wave or castle before the boss, where you keep farming gold until you are ready to try again.
Why enemies get stronger faster than you
Enemy health grows exponentially: in Idle Ronin it grows by about 55% per stage in the early game. Your power grows in steps, when you buy upgrades and reach milestones. Sooner or later the enemies pull ahead and you hit a wall. That is not a bug, it is how the genre is paced, and the walls are what make rebirth valuable. Our guide to breaking through a progression wall covers what to do.
Gear and equipment
Most idle RPGs add gear on top of levels: weapons, armor and trinkets that raise stats. Gear usually unlocks later, once the basic loop is familiar. In Idle Ronin, equipment crafting opens at stage 80, with more slots at stages 100, 150, 200 and 500, and set bonuses from stage 125. Gear is also where many idle RPGs hide their deepest choices: which set to build, which stat to reroll, what to salvage.
Summoning, merging and collecting heroes
How you get new heroes is what separates the sub-genres:
- Gacha summons: you spend currency on random draws. This is the model of hero collectors such as AFK Arena and Idle Heroes. See gacha, pity and drop rates.
- Drops: heroes come from bosses or chests. In Idle Ronin, the boss of every 5th stage drops a Unit Core that activates a random cyborg.
- Chains and merges: in Idle Summoner every tap on the monster gate tries to summon the next monster in a chain of 55, from the Slime to the Lord of the Abyss. A failed summon loses the monster and starts the chain over, unless you use a Resurrection Scroll.
Collections usually add a bonus of their own, which is why duplicate and low-rarity heroes are rarely useless.
Skills: the part you still control
Idle does not mean hands-off. Most idle RPGs give you active skills for when you are watching: a burst of damage for a boss, a freeze that stops the boss timer, a gold bonus. In Idle Summoner, Freeze deals ice damage and pauses the boss timer for a few seconds; in Idle Ronin each unit has an active skill you tap, and cooldowns keep ticking while you are away.
Rebirth: the reset that keeps it going
When the walls get too steep, idle RPGs offer a rebirth: back to stage 1 in exchange for a permanent bonus. Both our games unlock it at stage 50. Idle Ronin pays Rebirth Tokens (each +10% ATK); Idle Summoner raises your player level to the stage you reached (each level +1% damage). The details, and when to do it, are in prestige, rebirth and ascension explained.
Towers, dungeons and other modes
After the main stages, idle RPGs add side modes with their own rewards and rules:
- Towers: endless floors that get harder, often with a weekly ranking. Idle Ronin's Neon Tower has 300 floors; Idle Summoner's Tower of Infinity gives you 60 seconds to break as many floors as you can. See endless towers explained.
- Dungeons: short runs limited by keys, paying special resources. Each of Idle Ronin's three dungeons gives 2 keys a day.
- PvP arenas and guilds: fights against other players' teams, and groups that share rewards.
Offline progress in idle RPGs
Idle RPGs keep fighting while the game is closed. Some multiply your gold per second; Idle Ronin replays the fight for up to 8 hours, so your squad can clear stages while you sleep and stops at the first boss it could not beat in time. More in how offline earnings work.
What to upgrade first in any idle RPG
- Fill every team slot. Each hero or monster on the field adds damage, even weak ones.
- Spend where the gain per coin is highest. Games like Idle Ronin show how much ATK the next upgrade adds; compare that with the cost.
- Aim for milestones. A few levels that reach a x2 milestone beat many levels anywhere else.
- Keep the boss skills ready. Save your burst skill for the boss, not the waves before it.
- Do your first rebirth as soon as it unlocks. Any permanent bonus beats none.
- Do the daily modes. Dungeon keys and tower attempts refill every day and are wasted if unused.
FAQ
Are idle RPGs pay-to-win?
Some are, some are not. Look at the price range of in-app purchases on the store page and whether summoning is the only way to get strong heroes. Idle RPGs where heroes come from play (drops, chains, stages) are usually friendlier to free players.
Why can't I beat this boss?
Either your damage is too low for its health or you run out of time. Upgrade, use your burst skills at the start of the fight, and if nothing helps, rebirth. Stages ending in 4 or 9 are harder in many idle RPGs, including ours.
Do idle RPGs work offline?
Many do. Both of our idle RPGs play without a connection; ads, cloud save and rankings need one.
Sources
- ONI Games game code, September 2026: Idle Ronin (PlayerDatabase.CalculateEnemyHP, getEnemyHP, LiveOps.cs) and Idle Summoner.
- Google Play store pages (US) of AFK Arena and Idle Heroes, September 2026.
