In short: How to indicate that a numeric display represents the difficulty level?
I'm looking for a symbol that represents the concept of ever-increasing difficulty level, in the context of a casual puzzle game. Alternatively I could use a set of symbols that represent incremental levels of difficulty.
Difficulty level in this application is not something you choose -- it simply starts at 1 and increases without limit until the game is over. Think of a game like Tetris, where as the level increases pieces start falling faster, and the game only ends when the screen fills up.
Note: Two existing questions address how to present a user with a choice of difficulty levels when beginning a game. That's not what I'm talking about. The questions are:
Both for aesthetic purity and to dodge the localization issue I'm trying at all costs to not have words in my game, thus I'm looking for a symbol.
Right now I'm representing difficulty using a dial where the "digits" are the difficulty symbols from skiing (green circle, blue square, black diamond, double black diamond). I use these four symbols (plus a dash for 'zero') to represent a base-5 number. (See Option 3 below).
Even my immediate friends and family, though, have failed to catch on to that cue! And that doesn't bode well for residents of warmer climates, who may have no familiarity at all with the skiing symbols. (The existing question Which colors would best convey 3 difficulty levels? also notes that even these symbols and colors differ between North America and Europe).
So I either need a different set of symbols for my dials, or I need an single symbol next to the dial, which could change to simply being numeric, to signify that "this dial means the difficulty level".
Option 1: Prosaically, with words:
The problem with this: I don't want to use words
Option 2: A single symbol representing difficulty level:
Problem with this: I don't know of a symbol that represents difficulty level
Option 3: Symbols in place of digits:
The problem with this: People I've showed this to didn't understand it
The base 5 symbols, from North American skiing:
A display representing 00015 = 1:
A display representing 01425 = 47: