Roguelike Upgrade Ideas: Item and Perk Generator

Pick a genre, a rarity mix and how many upgrades you want, and get a pool of roguelike upgrades: each has a name, a rarity, an effect with real numbers, a stacking rule and synergy tags. Reroll single upgrades or the whole pool, then download it as JSON or CSV for your game or spreadsheet. It runs in your browser from hand-written effects, not AI.

Step 1 of 2: Genre
What kind of roguelike is it?

How to use it

  1. Choose a genre: Action, Deckbuilder, Auto-battler or Shooter, and press Next.
  2. Choose a rarity mix (Mostly common, Balanced or Rare-heavy) and 6, 12 or 24 upgrades, and press Generate upgrades.
  3. Press the reroll icon on any upgrade to swap it for a different one of the same rarity, or press Reroll all for a new pool.
  4. Press Download JSON for game data or Download CSV to tune the numbers in a spreadsheet.

How to balance an upgrade pool with rarity weights

This section is design advice, not data from real games. The rarity weights are relative: the chance of each rarity is its weight divided by the total of all four. With the Balanced mix (45, 30, 18 and 7, which add up to 100), each offered upgrade has a 7% chance to be legendary.

Think in offers, not single rolls. If the player picks from 3 upgrades after each fight, the chance that at least one of them is legendary is 1 minus 0.93 to the power of 3, about 20% with Balanced weights and about 9% with Mostly common weights (3% each). Decide how many legendary moments you want per run, count the offers in a run, and adjust the weight until the math matches.

Scale numbers by rarity so a legendary is clearly better but a common is never useless. In the generated pools, a legendary is usually three to four times as strong as the common version. Use multiplicative stacking for damage reduction and cooldowns so stacking copies never reaches 100%, cap anything that breaks the game at high stacks (life steal, move speed), and make run-defining effects unique so they leave the pool once taken.

Using synergy tags to make builds

Synergy tags such as fire, crit or discard mark which upgrades work together. A build forms when the player takes several upgrades with the same tag and one of them pays off the others, for example a poison upgrade that applies stacks and another that makes poisoned enemies explode.

Check the tag counts under the results. A tag with only one upgrade cannot form a build, and a tag with half the pool makes every run feel the same. For a 24-upgrade pool, aim for a few tags with 4 to 6 upgrades each, plus a few general upgrades such as max health that fit any build.

In your game, tags let you weight offers toward what the player already has, so a fire build sees more fire upgrades. Keep some randomness so players still discover new builds. The JSON download keeps tags as a list on every upgrade, so you can filter and weight the pool in code.

Frequently asked questions

What file formats can I download?
JSON and CSV. The JSON has the genre, the rarity weights and every upgrade with its id, name, rarity, effect text, number params, stacking rule, max stacks and tags. The CSV has one row per upgrade with tags separated by a vertical bar, ready for a spreadsheet.
Are the numbers balanced for my game?
No generator can know your game's health, damage and run length. The numbers are consistent starting points that grow with rarity. Expect to tune them after playtests.
What do the stacking rules mean?
Additive means every copy adds its full value. Multiplicative means each copy applies on its own, so two 10% damage reductions give 19% rather than 20%. Capped upgrades stop counting after 3 copies, and unique upgrades should leave the pool once the player takes them.
Can I use these roguelike item ideas in a commercial game?
Yes. Use, rename and change the upgrades in any free or commercial game.
Does the roguelike upgrade generator use AI?
No. It picks from hand-written effects for each genre and scales the numbers by rarity in your browser. Nothing is sent to a server.
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