Modifiers vs rerolls vs tables

 When you have a game system in your gamebook, the chances are they are to show what your character is good at and how good they are at it.

Also, you might want to give the character opportunities to get better at these things, such as with armour, tolls or magic items. Aside from winning a book, getting the highest stats possible is probably the second best measure of success (possibly tied with getting the most treasure or most magic items).

For example, the SKILL score in Fighting Fantasy is mainly a measure of fighting ability. The higher the character's SKILL score, the better they are at fighting. This is shown by rolling 2d6 and adding the results to SKILL. 

Another method of showing that someone is good at something is allowing them to reroll dice and picking the best option. This is my main mechanic in SCRAWL, but it pops up in other games (not usually as the main mechanic). It appears in blessings in Fabled Lands, Advantage in Dungeons and Dragons and occasionally in Fighting Fantasy.

Another method is by making a die roll and then referring to a table to see what the result is based on the roll and/one of your stats. This is how combat is determined in Lone Wolf. It is also how damage is determined in Advanced Fighting Fantasy.

Seems clear enough

However, adding random elements and numbers into a gamebook can come with problems because you then need to make sure that the gamebook isn't a cake walk or impossible. This is a tricky balancing act.

So how can you show that someone is good at something and what are the good and bad points of each method?

Modifiers (or stat scores that you add to dice rolls)

Modifiers add or subtract things from the dice rolls.

The good thing about modifiers is that they are the easiest way to see progression. Someone with a +3 modifier can easily see that they are better than someone with a +1 modifier. Modifiers also have no ceiling or floor (unless the game imposes one), so you can always get better and better and increase your modifier to as high as you can.

How else can you give the right stats for a 
giant, errrr tiger person.

If they are not carefully controlled, modifiers can make the game either way too easy or way too hard. Sure it's fun to get a +4 attack strength weapon, but now all combats lose their tension. Also, a spell might make you lose 4 SKILL instead of killing you, but that is basically a death sentence. 

The simplest way to control modifiers is to limit them to make sure that you don't give out too many or make them too big. 

Also, the range of the starting modifiers is always important. There are many Fighting Fantasy books that can be fixed simply by giving the starting character a SKILL score in a smaller range of 7-12. For example, the Warlock of Firetop Mountain has a lot of SKILL 5 goblins and orcs at the beginning. This makes combat busywork for anyone with a SKILL of 10+. It also requires you to defeat a SKILL 10 STAMINA 10 iron cyclops to get the treasure and kill the warlock without combat. That is very unlikely to do with a SKILL of 7. If the SKILL range was 9-11 or even 8-10, then then it will still be challenging without being impossible.

Another way of making sure that modifiers are not too high or too low is with a points buy system. Advanced Fighting Fantasy 2nd edition did this because the first edition had characters with a SKILL between 7 and 12. Since initial SKILL also determined the number of special skill points you could get and the special skill points were added to SKILL in tests, a SKILL 12 character way outclassed a SKILL 7 character.

This kind of system is also the reason why you can't travel the whole world in Fabled Lands all at once. Someone who starts in book 1 as a level 1 character can't just wander over to book 4 where the tests are catered to a level 4 character. Also, you can start in book 7 and head over to book 1 to steamroll over everyone.

Makes you wonder why the people of Nerech
don't just invade Sokara.

So modifiers are great if you want to make your character have no ceiling to their power, but you need to be very careful with your numbers to make sure that the game isn't either impossible or easy busywork.

Rerolls

Rerolls allow you to roll more dice than you need and then take the best result. If you want to have a penalty using rerolls, you can make someone roll again and take the lowest result.

The main thing about rerolls is that they don't increase the maximum score or lower the minimum score.

I use rerolls and not modifiers in SCRAWL. The reason for this is that SCRAWL is intended as a game where you can play any adventure in any order and at any stage of your career as an adventurer. This means that every test will have a difficulty between 3 and 6, so anyone can succeed or fail at them. The greenest adventurer could roll a 6 with a single die. The veteran can roll 3 dice on a difficulty 3 test (they have to roll at least 1 3 or higher) and all 3 of them could be below 3 so they fail. This means that no adventurer is excluded from an adventurer based on their experience level. This is the big advantage rerolls have over modifiers.

If I had modifiers in SCRAWL and started having difficulty 7 tests (where the character has to roll a 7 or more on 1d6), then any character who is not experienced enough to have the modifier is excluded.

Of course, some people might not like rerolls for the same reason. Having more rerolls might make the game easier, but it might not show too much progression as no matter how many rerolls you get, you can't get higher than the maximum dice roll. Rerolls worked for SCRAWL because it is an open game world where a character of any experience level could go anywhere in the world.

What? So a normal human couldn't survive this?

Tables

A table will take your result and then assign another number based on what the table states. The most common example of this is the Lone Wolf combat table.

If you squint at it, you see a puppy.

I'm not telling you what image this one is hiding.

Tables give you a lot of power over your game system. They allow you to have whatever number you want based on the difficulty. They allow you to limit bad effects and good effects so they don't go crazy.

If you look at the Lone Wolf table, then you will notice that the numbers are skewed in Lone Wolf's favour which means that combat is not so deadly for Lone Wolf. It also limits the bad effects against Lone Wolf as the effects are the same whether Lone Wolf's CS is 11 higher or 20 higher. This means it doesn't make combat a walkover for either side if the differences are obscene.

So the tables give you a lot of control and they let people increase their scores to as high as they want to be. The disadvantage is that they are not very elegant - the numbers are all there for you to see. Also, it increases the time as you both have to roll a die and then refer to the table.

So hopefully, this will give some ideas on which system to use to show progression and how to make sure the system stays both challenging and fair.

Happy gamebooking!