I've worked with Matope Swamp to provide them a number of custom additions to use on their forum. Matope is a closed pixel art Adoptables species, which operates primarily on a forum. Participation is largely free, based on RP events, raffles, writing contests, and games.
Add customizable achievements to your forum! No coding needed, manage it all from the admin UI.
Create your own achievements to be assigned to users. Achievement assignment can be done manually (including with a bulk assign/unassign ui) or automatically based on database fields. For automatic badges you decide what to reward. The script for automatic awarding runs every 2 hours, but you can configure that as needed. Achievements can also be assigned by providing a link to users that when clicked adds the assignment to their account (great for a puzzle or scavenger hunt).
Achievements show on profiles and users can select up to 4 achievements to show on posts.
This is built as an extension of functionality provided by SMFShop (I have no affiliation with SMFShop). The raffle system adds raffle tickets as a purchasable item for users. I also added the ability for admins to give items to users (including raffle tickets). Tickets are associated with a specific raffle and the admin can trigger raffle drawings including specifying the drawing reward. Raffle drawings generate a results page that everyone can see.
This adds the ability to roll dice as part of making or editing a post, but doesn't allow for modifying a roll after results are available to prevent cheating. Posts with dice rolls can be edited without interfering with the dice results. Dice are specified using input like '2d20+5'.