Look into the system a bit and be careful how you implement it. The system does tend to get bogged down, for example:
1. Roll a d100 to see if you hit
2. If you succeed, roll a d100 to see which location you hit
3. Roll dice+modifiers for damage
4. Calculate how much damage is done
5. If you deal critical damage, consult the relevant table of critical effects and roll a d10
6. If the table says to check another table, etc. etc.