What is a botch?
In Multiverser, there are three categories. Success, failure, and botch. The first two are relative, and the third often is.
A botch is when something happens that is totally not what you wanted. Botches occur most often when you are trying to learn somethign new that is challenging, or in a tough situation with the odds against you.
A botch in a combat situation tends to be more along the lines of dropping a weapon. Non-combat botches can be more flexible, and more lethal.
Tadeusz used pyrokinesis to melt glass, and botched. Became a torch.
MJ used telepathy on a rabbit. Botched. Ended up exchanging bodies with the rabbit.
Botches are one of the big ways versers head on to other universes.
My book is in the car, so I'm going by memory here..lets say, you have a Light spell (easy magic), and you want to learn Fireball (medium hard). After counting up all the benefits and distractions you end up with say a 60% chance of learning Fireball.
A "60" is your best roll. A 61 is a failure.
But 10% of the remaining 40% is 4. On a d100, 100-4=96. So on a 96 or better, you botch.
I then have a variety of options. I usually roll a GE roll, and if its a 3-4, you mess up, but in a way that benefits you. A 5 would be bad, perhaps dangerous (you set your coat on fire). A 30, and instant death--(you explode so fast you don't even know what happened.)
Now, if you tried a more complicated spell instead of fireball, or tried it in adverse conditions, or had a poor teacher, or whatever, you can see that you'd have a higher chance of failure and of botching.
Its also true that if you became a really good magician, and were careful, and you were learning a spell well within your reach, that you might have say a 125% chance on a d100 to learn it, and thus no chance to botch.
Graeme over on GO does this regularly with his spells. He's cautious, and well-prepared, and he's not trying to open a gate to the Nether Planes or summon a Dragon so he usually has zero chance of botching.
Its also true that you could have a skill that is really well understood, and botch it. Say you're an excellent computer programmer...but the terrorists are pumping tear gas and bullets into the room as you type...you might end up botching and turning on the Ray Cannon of Doom instead of turning it off.
Now, MJ at GO does this game design explanation a lot better than I, since he's the game designer, and I'm more of a setting designer.
Clear as mud?
PT