Height and Weight (Houserule)

==Height & Weight==
The 4th Edition GURPS rules relate a character’s height to their strength and their weight is unrelated to it. Nor does being overweight or fat affect your physical abilities. Frankly, in a game that I value for its excellence at reflecting the real world, I find these rules to be a major flaw.
Take a few well-known examples from popular TV programmes. Do you imagine that Sheldon Cooper from The Big Bang Theory at 6’1” is stronger than Agent Cho of The Mentalist at 5’10”? Can you picture Roseanne being a superb acrobat, able to swing one-handed from a chandelier, grab a McGuffin in passing, then release and do a flying forward roll out of the window?
I have worked out the following table of weight by height and strength:
Build Table: Core Weight in Pounds by Height & Strength
ST	
4'11"	
5'	
5'1"	
5'2"	
5'3"	
5'4"
6-8	
86	
89	
92	
94	
99	
102
9-11	
108	
112	
116	
120	
124	
128
12-13	
129	
134	
139	
141	
148	
153
14-15	
162	
168	
174	
177	
186	
192
						
ST	
5'5"	
5'6"	
5'7"	
5'8"	
5'9"	
5'10"
6-8	
105	
108	
112	
115	
118	
122
9-11	
132	
136	
140	
144	
148	
153
12-13	
158	
163	
168	
172	
177	
183
14-15	
198	
204	
210	
216	
222	
229
						
ST	
5'11"	
6'	
6'1"	
6'2"	
6'3"	
6'4"
6-8	
125	
129	
132	
136	
140	
144
9-11	
157	
162	
166	
171	
175	
180
12-13	
188	
194	
199	
205	
210	
216
14-15	
235	
243	
249	
256	
262	
270
By ‘core weight’ I mean the weight of a normal proportion of muscle, bone, and fat for someone of your height and ST. You will be about the weight given, but you can choose to vary it by about 10% either way because of variations in your physique – lean but strong, stocky without being fat, etc. Even though it includes fat (about 20% of body weight, a healthy level), this weight doesn’t count as ‘overweight’/’fat’ etc. for encumbrance purposes. 
The figures are derived from Body Mass Index: an ‘average’ person of ST 9-11 will have a ‘medium’ BMI. ST 6-8 will be pretty skinny – 20% lower weight than average, 12-13 is 20% heavier, and the top strength allowable in my campaigns (50% above racial average) is 50% heavier.
Overweight: 
The 4th Edition rule about excess weight not affecting physical performance is a poor choice, in my view. It runs so contrary to what we all know of the real world that it jars. I cannot imagine fat people performing physical actions at the same level of ability as an ideally-built person with the same level of fitness. I liked the GURPS 3rd Edition system of excess weight being treated as Encumbrance, but decided that to make the impact of being overweight consistent with the cost of its effect on a character’s Dodge score, it needs to be tweaked somewhat. The cost of each level of overweight includes points for the social and practical disadvantages (restricted choice of clothing, people don’t find fat people attractive in most of the settings we play in, and the various other restrictions listed in the Characters book), and an additional amount to compensate for the effect on Dodge. 
Overweight people have enough excess weight to take them halfway to Lightly Encumbered (round up) even when carrying nothing but normal clothes. -15 points
Fat people’s excess weight takes them to the minimum for Lightly Encumbered (that’s -1 to Speed, Move, and Dodge). -25 points
Very Fat people are so heavy that they start at Medium Encumbrance (-2 to SM&D). -50 points
Thus a ST10 Overweight person will have 10lb encumbrance of fat, a Fat person 20lb, and a Very Fat person 40lb. The equivalent for ST14 will be 20lb, 78lb, and 117lb. (NPCs may go up to Morbidly Obese: Heavy Encumbrance.)
If a player wants their character to be Very Fat but not suffer for it in combat, they can of course spend 40 of those points to buy +2 Speed, which will cancel out the effect of that encumbrance on their Dodge (and initiative, for those who use the standard initiative system – I use my Initiative house-rule). Or they could spend the 40 points to increase their Move. This reflects those few people who are fat, but fit enough to match slimmer people in some aspects of physical performance. 
GMs whose campaigns feature Fatigue Points regularly may want to increase those point values. My campaigns hardly ever feature ‘endurance’ scenarios where the characters cannot sit down and rest at regular intervals during or after exertion, so we rarely bother monitoring Fatigue Points except when casting magic. But if for example you are running a Zulu campaign where the characters are expected to run for four days and fight a battle at the end of it, you may want to increase the value of the disadvantage. Characters with 78lb of excess fat wobbling around their bodies will probably need to buy Very Fit just to keep up with those whose only encumbrances are a loincloth, shield, knobkerrie, and assegai.