The other cars you compete against in RR3 - referred to as robots, or simply bots - are controlled by the app itself.  The performance of bots is modified by the app, by making them faster or slower, to make the game as challenging as possible (without being impossible) for a wide variety of player skill levels.  If you win consistently, especially by large margins, the bots will get faster and faster.  Or if you lose repeatedly, the bots will become slower.

The expression "dumbing down the bots" refers to the process of losing an event over and over to make it easier to win.  This process usually affects other events within a Series (or RR3 special Challenge), allowing you to pick an event of short duration (like an Elimination event, for example), to slow down the bots for other events in the same Series.

Challenges can refer to two different things:

• In RR3, it refers to special "Series" that are introduced regularly, usually with prizes of free cars for successful completion.
• In MRR, it refers to events hosted by MRR members, listed in the Challenges section of the site (link in top menu bar).  Challenges can run for a specific period of time, or be ongoing with no end date.  When you post an entry (the results of running the specified event) for a Challenge, it is automatically included in with all the other ULB entries for that event.

Team MRR number works just like the numbers racecar drivers have on their cars in the real world.  MRR members may choose a number, which must be unique, and save it in their member profile.  When customizing their cars in RR3, they include their driver number so that they can be easily identified when their cars appear in races in another player's app.