# Roll and Keep Helper > Dice roller and probability calculator for roll & keep RPG systems. (iPhone/iPad app by Jay Luo.) - Source: https://appshunter.io/ios/app/roll-and-keep-helper/id921422193 (this page in markdown: same URL + `.md`) - Developer: [Jay Luo](https://appshunter.io/developer/729686872) - Category: Games, Role Playing, Utilities - Price: $0.99 - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 12.0 · 1 MB - Languages: English - Released: 2014-10-05 - Data updated: 2026-06-24 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/roll-and-keep-helper/id921422193/reviews.md ## What is Roll and Keep Helper? Die roller and probability calculator for role playing games using the roll & keep dice system. Set a number of 10-sided dice to roll, and a subset of these to be kept. For each roll, the total is compared to a target number. The Roll and Keep Helper can simulate die rolls and calculate the probability of hitting a target number. It also calculates the probability of successfully calling 1, 2 or 3 raises (hitting increased target numbers). You can enter the number of dice to roll and keep, the target number, and an optional static bonus using either the + and - keys or you can use a numeric keypad by tapping the number you want to change. Use the tab controls at the bottom to switch between die rolling mode and probability mode. While in die rolling mode, you can shake the phone or press the button to roll the dice. By default the 10-sided dice will explode on 10s (causing another die to be rolled and added to the total), but the Roll and Keep Helper can be also be set to explode on 9s and 10s, to have no explosions, and/or to reroll 1s once. No ads or in-game purchases. Estimating the chance of succeeding on roll & keep die rolls, and how many raises you can safely call, is tricky and I wrote this utility to help. Hope you enjoy it! ## Key features - Simulates roll & keep dice rolls - Calculates probability of hitting target numbers - Estimates probability of calling raises - Customizable dice explosion and reroll settings - Supports static bonus addition - Tab controls for switching between rolling and probability modes ## Frequently asked questions about Roll and Keep Helper ### What is Roll and Keep Helper used for? Roll and Keep Helper is a utility designed for role-playing games that use the roll & keep dice system. It helps players simulate dice rolls and calculate the probability of achieving specific outcomes, such as hitting target numbers or successfully calling raises. ### Does Roll and Keep Helper have ads? No, Roll and Keep Helper is ad-free and does not contain any in-game purchases, providing an uninterrupted user experience. ### How does the dice explosion feature work in Roll and Keep Helper? By default, 10-sided dice in Roll and Keep Helper explode on a roll of 10, meaning another die is rolled and added to the total. This can be customized to explode on 9s and 10s, or to have no explosions at all. ### Can I reroll dice with Roll and Keep Helper? Yes, Roll and Keep Helper allows for the rerolling of 1s once, which can be enabled or disabled according to your game's rules or your preference. ### What devices is Roll and Keep Helper compatible with? Roll and Keep Helper is available for iPhone and iPod devices, running on iOS. ### How often is Roll and Keep Helper updated? The latest version, 2.1, was released on June 19, 2022. While specific update frequency isn't detailed, the app has been maintained since its release in 2014. ### What is the price of Roll and Keep Helper? Roll and Keep Helper is a paid application, available for $0.99. ### What is the age rating for Roll and Keep Helper? Roll and Keep Helper has an age rating of 4+, making it suitable for a wide range of users. ## Version history (last 2 releases) ### 2.1 — 2022-06-19 Version 2.1: updated app for iOS 12+. ### 2.0 — 2014-10-04 This app has been updated by Apple to display the Apple Watch app icon. ## More apps by Jay Luo - [Sub Command](https://appshunter.io/ios/app/sub-command/id789382250) - [Meters & Milliradians](https://appshunter.io/ios/app/meters-and-milliradians/id1015755731) - [Samurai Scroll](https://appshunter.io/ios/app/samurai-scroll/id1626309531) - [Combat Space Patrol](https://appshunter.io/ios/app/combat-space-patrol/id6450519149) All apps by Jay Luo: https://appshunter.io/developer/729686872 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-24.*