That is when the conversations about loaded dice come in to play. Having researched 'biased coins', it appears that these are the unicorn of the mathematical world; unless you have a double-sided coin, of course.
After thinking about the question above, I set myself the challenge of sourcing the above items. I am now the proud owner of a double-headed coin and a loaded die. Armed with these pieces of equipment I am just itching to tutor my next lesson on probability!
Before I go though - "Heads I win, tails you lose!"